# Blue-Green Algae (Cyanobacteria)



## shudaizi (Jun 9, 2020)

Hi El Naturals ...

So about 19 days ago, we started over fresh on our 12x12x12 (7.5 gal) cube. And it was going well. Many plants were growing, pearling from certain plants almost every day. 

We started noticing some algae issues (brown diatoms I think) about 10 days ago, so we added two nerite snails and a few more Vallisneria plants. 

But in the last five or six days, we are getting BGA (cyanobacteria) coating lots of leaves, the rocks, etc. Only small bits on the soil and a thin patch here or there on the glass. The nerites have been cleaning off the diatoms and sometimes it seems the BGA too, but only on the hardscape (rocks and wood) -- they're not keeping up in that the BGA is on the plants themselves. I try to clean it off and remove it as best I can, but I'm not really making much headway. Seems it always bounces back by the next day. And the plant growth has slowed down. Some evenings the only "pearling" has been the BGA on the rocks! I'd upload a picture but honestly there's not much to see: the patches of BGA are small, thin, and scattered, so they don't really show up on pics that well. But there is a quite a number of them -- many leaves have tinges of that fluorescent blue-green along the edges unless I spend hours picking it off leaf by leaf. 

I am still seeing signs of plant growth. The Anacharis is still growing strongly. The Salvinia are reproducing on the surface. I see some new hairgrass blades and roots and new leaves on some of the crypts. The Vals are rooted in very strong, but haven't really put up new leaves or visible runners. The Amazon swords are rooted down tight.

So, is the BGA just part of the "new tank chaos" that Diana talks about and I should just be patient? Will the plants tip the balance back on their own? Or is this a critical issue that could quickly get out of hand and portents a future crash? If it's the latter, what can I do? I have a UV sterilizer (3 watt) that just arrived today and I put it in the tank, but obviously it's too soon to know if that will have any effect. Anything else beyond the 2-3 day "blackout" treatment?

EDIT: Here's yesterday's test results in case it helps. 
pH: 7.0
Ammonia: 0
Nitrite: 0
Nitrate: 5ppm
GH: 5 (a bit lower than I might like)
KH: 5 (a bit lower than I might like)
Phosphate: 5ppm


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## Weaveman (Dec 13, 2019)

https://www.amazon.com/dp/B000QSK31M/ref=cm_sw_r_cp_apa_i_ns.pFbKQ9M20C

After a severe outbreak in my 75g I used this product as a last resort. It cleared up with one treatment and I've seen no negative effects so far (3 weeks)


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## shudaizi (Jun 9, 2020)

Amazon reviews make it seem a miracle product. It didn't hurt your nitrogen cycle (ammonia / nitrite spike)?



Weaveman said:


> https://www.amazon.com/dp/B000QSK31M/ref=cm_sw_r_cp_apa_i_ns.pFbKQ9M20C
> 
> After a severe outbreak in my 75g I used this product as a last resort. It cleared up with one treatment and I've seen no negative effects so far (3 weeks)


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## mistergreen (Mar 3, 2007)

I would remove the BGA and reduce the lights. No need for quick cures.


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## shudaizi (Jun 9, 2020)

mistergreen said:


> I would remove the BGA and reduce the lights. No need for quick cures.


Reduce light duration or intensity? (Removing the BGA off every leaf ... those Bacopa leaves are pretty tiny ... could mean breaking down the tank more or less....  I should just make this the Groundhog Day Tank ... break it down and start over every 3-5 weeks.)

EDIT: On a more serious note, I wish I knew what the underlying cause is. Seems cyanobacteria in aquariums has lots of possible causes, some of them exact opposites (nitrates too high, nitrates too low). But none of the usual suspects sticks out as fitting my water parameters. So I'm left with mainly confusion and not really knowing what to "fix". I do know that spending 90 minutes a day scrubbing leaves is not gonna be feasible for much longer -- I've had time to spare during the summer, but the semester is starting up and my time is soon going to be taken up with lectures, seminars, grading papers, and faculty meetings. Kinda hoped the El Natural would lead to minimal time expenditure, but so far it's been the exact opposite. Some people seem to get it right and the tank just takes off (due to skill? luck?) but clearly that's not me.


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## Weaveman (Dec 13, 2019)

"Amazon reviews make it seem a miracle product. It didn't hurt your nitrogen cycle (ammonia / nitrite spike)?"

No, it hasn't so far. I really didn't want to use a product, but like you I was at my wits end with bga coming from out of the blue with no discernable difference (switched to nls pellets from bug bites, but parameters didn't change), and a reeftank to look after. Even tried weekly 50% w/c with no difference. I will say the vial came cracked and I almost didn't use it.


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## Weaveman (Dec 13, 2019)

I should say that I did remove as much as was practical during a w/c which I had done several weeks in a row, before adding it.


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## shudaizi (Jun 9, 2020)

I've been doing that the last couple of days -- rubbing as much off leaves as I could and then doing a targeted w/c to get all the suspended bits of BGA out before it settles. (Since it's such a small tank, I use airline hosing for the siphon -- it's slow but gives me time to target specific spots or suspended detritus without removing too much water. A regular hose just drains the tank too fast and sucks plants right out of the substrate. Been there, done that.) But, like the nerites, this hasn't really seemed to make much of a difference and it is taking more time than I will have on a daily basis starting in about two weeks.

In any case, good to know The Product didn't seem to harm your nitrogen cycle. 



Weaveman said:


> I should say that I did remove as much as was practical during a w/c which I had done several weeks in a row, before adding it.


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## FlatfishTanker1 (Mar 13, 2020)

New tank chaos is definitely a possibility. It depends on what kind of soil you used in your tank. If there's a lot of plant matter and/or fertilizers in the soil, it will break down and leach into the water column causing an over-abundance of nutrients that algae takes advantage of. This is why you need to do lot's of water changes initially. For how long, I don't know. Some people mineralize their soil before they start up a soil tank. This helps to pre-break down the plant matter in the soil and eliminate some of the ferts and nutrients that can cause these problems initially. Not everyone believes this is a good way to pre-treat your soil, but many do. There are good threads and directions about how to do this in these forums. I mineralized my soil before I started a few tanks recently, and I feel like it helped. I still get a small amount of algae and diatoms - I think everybody probably does. But so far, It hasn't been overwhelming. I am right now running a UV sterilizer in one of my tanks to see if it helps. So far, so good. It's not going to kill algae that's already taken hold, but it might help slow the spread and remove bacteria that may be feeding it.


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## mistergreen (Mar 3, 2007)

Try using a toothbrush to brush off the algae. Vacuum it out of the tank.


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## shudaizi (Jun 9, 2020)

FlatfishTanker1 said:


> New tank chaos is definitely a possibility. It depends on what kind of soil you used in your tank. If there's a lot of plant matter and/or fertilizers in the soil, it will break down and leach into the water column causing an over-abundance of nutrients that algae takes advantage of. This is why you need to do lot's of water changes initially. For how long, I don't know. Some people mineralize their soil before they start up a soil tank. This helps to pre-break down the plant matter in the soil and eliminate some of the ferts and nutrients that can cause these problems initially. Not everyone believes this is a good way to pre-treat your soil, but many do. There are good threads and directions about how to do this in these forums. I mineralized my soil before I started a few tanks recently, and I feel like it helped. I still get a small amount of algae and diatoms - I think everybody probably does. But so far, It hasn't been overwhelming. I am right now running a UV sterilizer in one of my tanks to see if it helps. So far, so good. It's not going to kill algae that's already taken hold, but it might help slow the spread and remove bacteria that may be feeding it.


The first abortive attempt in this tank was with exclusively organic soil -- the disaster is well documented in a different thread. But for the redo, I used topsoil that is 75% mineral (i.e., NOT high in organics -- hill excavation almost certainly) and the 25% that was organics was very aged / decomposed / mineralized at the company that makes the topsoil. So, I'm doubtful that it's the usual high spike from organics that's at root of this BGA.

With that said, it's possible that I haven't been doing as many water changes as I should have; though it's easily been more than 50% per week. I can up the frequency for sure as they don't take much time, really.


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## chodovet (Jul 17, 2020)

I've just started to get some BGA in my new-ish tank as well... but it's only growing on the roots of Pothos that are very close to the surface (and therefore to the light), so I think it must be light-related. Though perhaps there are other contributing factors as well? Hoping to hear from some experienced folks more about the underlying causes...


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## dwalstad (Apr 14, 2006)

No ingredients were listed for this product, which to me is problematic.

My guess is that this magic brew contains antibiotics, either kanamycin or erythromycin. Either of these antibiotics will work. My experience is that they cleared up BGA very nicely and quickly--within a day. 

It's been years since I've had BGA. I think I just used the recommended dose for treating fish. If a single dose doesn't work, then you may have an antibiotic-resistant BGA. Be careful about increasing the dose.

I would remove as much of the BGA as you can before treatment. A mass of dying/dead BGA could easily release toxins into the water. And some BGA produce some very nasty toxins.


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## shudaizi (Jun 9, 2020)

dwalstad said:


> No ingredients were listed for this product, which to me is problematic.
> 
> My guess is that this magic brew contains antibiotics, either kanamycin or erythromycin. Either of these antibiotics will work. My experience is that they cleared up BGA very nicely and quickly--within a day.
> 
> ...


I too am always skeptical of things that don't include the ingredients -- always wary of snake oil.

In reading through the amazon reviews out of curiosity, one reviewer said they investigated by testing their water and samples after dosing and discovered that the product jacks up the GH to super high levels, perhaps to "shock" the BGA and thus (the reviewer felt) is likely not to be an antibiotic. No idea if that's right or not, but I found it interesting. Wondered about dumping my stock CaCl solution into the tank to see if it kills off the BGA ... (I jest!)


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## mistergreen (Mar 3, 2007)

I think the product also said it reduces O2. It's some chemical for sure. It could be formaldehyde.


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## shudaizi (Jun 9, 2020)

dwalstad said:


> either kanamycin or erythromycin. Either of these antibiotics will work. My experience is that they cleared up BGA very nicely and quickly--within a day.


I've scouted around and erythromycin is easily available but usually "not recommended" for new tanks as it does a number on nitrifying bacteria too. Kanamycin (not blended with any other medication) is only available for as I can tell in amounts and cost that make it somewhat prohibitive ($80 for 100 grams). Seachem's Kanaplex is reasonable but has Kanamycin blended with something else (Nitrofurazone?) -- seems it's similar or identical to AAP's Spectrogram. Is that what you would recommend, Diana? Or is the blend to be avoided?


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## dwalstad (Apr 14, 2006)

shudaizi said:


> I've scouted around and erythromycin is easily available but usually "not recommended" for new tanks as it does a number on nitrifying bacteria too. Kanamycin (not blended with any other medication) is only available for as I can tell in amounts and cost that make it somewhat prohibitive ($80 for 100 grams). Seachem's Kanaplex is reasonable but has Kanamycin blended with something else (Nitrofurazone?) -- seems it's similar or identical to AAP's Spectrogram. Is that what you would recommend, Diana? Or is the blend to be avoided?


I'd use either the inexpensive erythromycin or Seachem's Kanaplex. I wouldn't worry about the nitrifying bacteria; they'll come back and your plants should be taking up ammonia.

Just looked at my book [on page 158] where I recommend using these antibiotics _at half the dose _recommended for treating diseased fish. I would go with that. (My book is more reliable than my memory.)


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## aquabillpers (Apr 13, 2006)

When I set up a new soil-based tank I sometimes get a small amount of BGA. I treat it with erythromycin and it goes away with no apparent aftereffects.

BGA has its own kingdom that it shares with bacteria. (The other 4 are animal; vegetable; fungus et al; and protozoa.) https://www2.palomar.edu/anthro/animal/animal_3.htm

There are probably at least 1000 species of BGA, most harmless, some dangerous.

Bill


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## shudaizi (Jun 9, 2020)

aquabillpers said:


> When I set up a new soil-based tank I sometimes get a small amount of BGA. I treat it with erythromycin and it goes away with no apparent aftereffects.
> 
> BGA has its own kingdom that it shares with bacteria. (The other 4 are animal; vegetable; fungus et al; and protozoa.) https://www2.palomar.edu/anthro/animal/animal_3.htm
> 
> ...


Cool info!

I found it in my hospital tank too -- which is housing extra plants and a mystery snail that the betta fish took exception to. (After two days of being swirled at constantly, the snail was floating at the top of the tank -- after two more days with him never daring to come out, we put him in the quarantine tank.) It just exploded in there in the last 36 hours as I didn't see any yesterday morning. That tank doesn't even have soil, just the black diamond blasting sand, some slow growing epiphytic plants (Java trident ferns, water wisteria, and a couple small Bucephelandra), and the snail. Ugh.

So, I'm thinking I'll have to dose both tanks to clear them up. I've been doing daily cleanings and small water changes in the 7 gallon. Those with the UV sterilizer have made a difference for sure, but it's not really going away yet -- if I miss a day, the BGA bounces back pretty fast. And I can't really clean the floating Salvinia at all and they're increasingly covered in it. (They should be easy to dose.)

I did find some small amount (i.e., more affordable Kanamycin) which supposedly isn't quite as harsh on nitrifying bacteria, so I'll try that once it arrives. I'll also be reducing the light duration by an hour and see if that helps too.

Mainly, I'm just worried that I haven't identified the underlying cause and that it'll just come back. Hopefully my experience turns out to be the same as yours, Bill!


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## shudaizi (Jun 9, 2020)

So, a couple quick (hopefully last!) questions for those who have used kanamycin or erythromycin for Cyanobacteria. 

1. have either of these (at half dose) hurt plants or inverts (snails) in your tanks? 

2. do you remove the medication (via carbon in filtration)? if so, after how long? or do you remove it slowly through regular water changes?

EDIT:

3. should i leave the UV sterilizer running throughout the treatment? or remove it?


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## Bucha (May 22, 2016)

Hi Shudaizi,
I am a Dutch person, not El Natural, so may be my advice is irrelevant. I have the best results (no cyanobacteria) when I keep Nitrates at 10ppm and Phosphates at 2ppm. Cyanobacteria can synthesize nitrates from nitrogen, so it tends to out-compete all plants when Nitrates levels are low. On the other side, cyanobacteria tends to "hoard" phosphates, because it often is a limiting nutrient for BGA. You have 5ppm Phosphates - a bonanza! So you BGA may be "thinking": Good times! Let us multiply! 
Moreover, unless I have phosphate-loving plants (such as Rotala Wallichii, Limnophila Hippuridoides, etc.), I keep Phosphates even lower: at 1.5ppm.
Also, for dKH 5, pH 7 corresponds to 15ppm of CO2 available to plants in your water. I usually need at last 30ppm to avoid BGA.


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## Bucha (May 22, 2016)

No, Please do not use antibiotics for BGA! I used to use erythromycin when I was a beginner: first the BGA cyanobacteria is gone and all plants grow very fast, in 4-6 weeks black-beard cyanobacteria appears and it is the end of the tank! No, antibiotics do not hurt plants or inverts (snails) or fish, but they totally destroy the emerging bacterial ecosystem. Do not do it!!!


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## entireleaves (Mar 25, 2005)

For me the only thing that has been reliable has been erythromycin. I have tried H2O2 and that Blue Green Slime remover product and they clear it up short term but it always comes back. Furan2 also wiped it out in a quarantine tank but it also completely destroyed some Bolbitis I had growing on the driftwood in that tank.

ETA: in reply to post above I have never had an ongoing issue after use of erythromycin.


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## Bucha (May 22, 2016)

H2O2 is very harmful to fish. Look, the invisible bacterial community is responsible for the health of any algae-free tank. Before I start a new tank, I do not clean the filter in an old (successful) tank for 2 months, then I buy a new filter for the old tank and transfer the old filter to the new tank without cleaning. The hope is to transfer the successful bacteria established in the old tank to create the same bacterial community in the new tank. It often works. Sometimes it does not, and I have to suffer through wait and daily cleanings of the new tank until it established the bacteria it wants. Antibiotics (erythromycin) kills most bacteria, then it is a gamble. May be some people get lucky, I never did. I used erythromycin twice with bad consequences in the past. Half a year ago I purchased several very expensive plants, they were grown underwater and had difficulties adapting, the cuttings were also very small, I also went away for a few days and my nitrates fell to almost zero. I saw cyanobacteria colonies at the growing tips of new plants. Over-confidently I decided to use erythromycin, got infestations with black beard on the soil, had to change all soil.
People use the antibiotics for almost a hundred years. Bacteria have capability to exchange genes for antibiotic resistance. Erythromycin will certainly kill your BGA, it will also kill most other bacteria in your soil and your filter, so only those that have the resistance gene will survive. They may not be the ones that you want!


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## shudaizi (Jun 9, 2020)

Hi Bucha,

I'm happy to listen to all advice. My question about phosphates is how do I lower them "permanently"? I can do water changes, yes. But from the day I've gotten the phosphate test kit I have always registered 5ppm, consistently. Whether I'm doing 30% water change every other day, to when I go two weeks without. Whether it was the first (disaster) tank or this redone one. So, I'm somewhat at a loss about how to remove the phosphates if that is indeed the problem. I only have ONE fish in there, so it can't be coming from the fish food (and I got the exact same phosphate levels when I had NO fish in there too). 

And sure enough, just tested my tap water -- it seems that I have about 5ppm phosphate straight out of the tap. Is there an inexpensive way to get rid of the phosphate without using RODI water (not an option)? 

Truly, I'm on the cusp of tossing in the towel. Few things are worth as much time, energy, and money as I've put into this 7.5 gallon tank in the last two months.


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## mistergreen (Mar 3, 2007)

H2O2 is not harmful in the right quantity. I use it often, 1ml/gallon. I squirt it directly on the algae. A great cure for algae is a balanced tank parameters though.


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## SamXp (Mar 12, 2020)

shudaizi said:


> So, a couple quick (hopefully last!) questions for those who have used kanamycin or erythromycin for Cyanobacteria.
> 
> 1. have either of these (at half dose) hurt plants or inverts (snails) in your tanks?
> 
> ...


I used the exact same product listed in the amazon link above, back in June. First, did a 100% water change and removed as much cyanobacteria as I could. Scrubbed the Anubias leaves. Removed the hornwort and guppy grass that was coated in it (put fresh clippings in from another tank so the plant load remained mostly the same). Replaced the floating plants, as well. 
Cyanobacteria melted away and hasn't come back.
I did the regular dose and the snails were ok.
I don't use carbon in filtration.


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## Bucha (May 22, 2016)

Do not give up! Planted aquarium is hard and it can not be fully controlled, it always need persistence and a bit of luck. It is very strange that your tap water has 5ppm of phosphate, usually it has zero. In my experience nitrates come from fish feeding, phosphates need to be added weekly, sometimes twice a week to keep their level at 1.5-2ppm. I always feed with frozen blood-worms (you can find tiny ones for small fish), I found that most flake foods produce too much of unwanted dirt in the tank and ruin the balance. Your tank is only 7.5 gallons. You can buy distilled water for the water changes. My tap water is very hard in Winter, ant too soft in Summer. So I buy for the winter:
https://www.amazon.com/gp/product/B00DSP57BQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The replacement resin:
https://www.amazon.com/gp/product/B076ZWCVN8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Of course you need to re-constitute the distilled water to add nutrients. I use the following (works for me). All needed chemical are inexpensive on Amazon, some are cheap at grocery/pharmacy (see below)
THE AMOUNTS CALCULATED TO ADD 1 PPM to 41 GALLONS TANK (155 LITERS) , you can easily re-calculate them to any volume.
Nitrates, Desired: 10ppm. 253 mg KNO3
Phosphates, Desired 2ppm: 217.5 mg KH2PO4
Potassium, Desired 14ppm: 397 mg KHCO3
Sodium, Desired 21ppm: 566 mg NaHCO3 (baking soda) or 394 mg NaCl (table salt)
Calcium, Desired 15ppm, 569 mg CaCl2*2H2O
Magnesium, Desired 5ppm, 1.57 g MgSO4*7H2O (Epson salt, any pharmacy) or 1.30 g MgCl2*6H2O

I hope I presented the amounts in understandable form. Do not mix Ca and Mg with the rest, they will precipitate, add each Ca and Ms separately. Add Iron and micros in several hours, after all the rest is mixed.
If you do not have sensitive scales (measure mg) you can make concentrated solutions (measuring in grams) and dilute them/add small amounts.
I am very sorry for making it difficult, but it is better than to give up! Plants do not just need Potassium and Magnesium, they meed the right ratio of K/Na and Ca/Mg. My tap water at dKH 5 has essentially zero Mg, all or it was Ca.

Some other useful calculations for carbonate hardness:
To add 0.5dKH to 41 gallons (155 liters) use: 2.77g KHCO3 or 2.32g NaHCO3


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## Bucha (May 22, 2016)

Easy option: may be try to introduce a very fast growing plants such as water wisteria. It will wipe off all your nutrients and may out-compere the BGA. It is an easy option and does not require measuring advanced chemicals. Then you can add nitrates and not phosphates.

If you add carbonates NaHCO3 or KHCO3 your pH will go higher. Do it slowly.

Last thought. I am a Dutch person, for our corner of the hobby the small 7.5 gallons cube is the HARDEST and most advanced option. It is very hard to support stable ecosystem in less then 40 Gallons. It is much harder to have slow-growing plants than fast growing plants. Also, may be your excess of phosphates comes from the soil? Do not give up. I was desperate many times, lost many tanks, it is a difficult hobby. But a successful tank is just too beautiful to give up.


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## shudaizi (Jun 9, 2020)

Already have Water Wisteria in the tank. The BGA is outcompeting it -- I have to clean its leaves every day. But, that might be only temporary as it came with emersed leaves and they're the ones that get colonized by the BGA quickly -- the new submersed growth stays much clearer. But perhaps the real question is whether it will win the race before the BGA has wiped out the rest of the tank.

Since it's a small tank, I switched to bottled water (tested at 0ppm to trace phosphate). Did about 50% water change. Phosphates down to ~2ppm. Will see if that helps. Will do a couple more smaller changes in the next couple of days. 

Of course, all the water changes mean that I just lowered my already low nitrates too. So might just make things worse for plant growth rather than better. The Vallesneria were already struggling; looks like they might just be done for in the next week or so. Seems I'm doing something quite wrong (again!), but really not sure what. 

And really, if it doesn't turn itself around in the next couple of weeks, I'll likely fold up shop on the aquarium. My day job (professor) takes enough mental effort and time (about 70 hours a week during the academic year) that I really don't need my (very limited) free time to be this hard, demand this amount of time on a daily basis, or require advanced degrees in science.


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## Bucha (May 22, 2016)

Hi Shudaizi,
I have just posted a big post about the nutrients on the general forum. I checked the numbers (I think in liters and messed up the previous post - it was 155 Liters, not Gallons). I also calculated an example it that big post. It describes how to keep nitrates/phosphates after water changes. I hope you can find my new post and it will help you. I also work A LOT, but the planted tanks actually take the stress away (after a steep learning curve and a lot of initial frustration). If you do not give up, please, contact me at the end of September (when the weather is not so hot) and I will send you some of my beautiful and rare bucephalandra for no money, as the encouragement - perfect plants for a small tank, gorgeous. I do not know how to send a private message here, but it should be possible for you to give me the shipping address. What substrate do you use? I had the best luck with Seachem Flourite Black Clay Gravel (GRAVEL, not sand-like black substrate)
https://www.amazon.com/gp/product/B0019J0ISU/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1


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## dwalstad (Apr 14, 2006)

shudaizi said:


> I switched to bottled water (tested at 0ppm to trace phosphate). Did about 50% water change. Phosphates down to ~2ppm. Will see if that helps. Will do a couple more smaller changes in the next couple of days.


Trying to reduce phosphates in an aquarium is a totally lost cause. Every pinch of fishfood only adds more P. Plus algae are much more adept than plant in using phosphates.

Using RO water won't help and will eventually hurt your ecosystem, as it contains no calcium or other hardwater nutrients. You will see most plant melt away fast. I also shudder for health of fish.

The trick is to have a soil substrate that contains insoluble iron that algae has no access to, but that rooted plants do have access to. If you can get rooted plants growing well, they will drain the water of soluble iron so that algae cannot grow (my book, pp. 167-170). The whole idea is based on the insolubility of iron in oxygenated water but its very great solubility--and availability to plant roots--in the substrate.

If providing iron from the substrate doesn't work, which it sometimes does not, then you move on to manual removal of algae and a one-time treatment--if BGA is the problem--of erythromycin. This is a surgical killer that gives you a little breathing room. You can add extra plants, etc. Often, though, I've found that a one-time treatment with erythromycin was all that it took to shift the ever-present competition between plants and algae back to the plants.


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## Weaveman (Dec 13, 2019)

Six quality papers googled on the iron idea above. I think she may know her stuff. Wasn't sure if iron is as critical to cyano as it is to algae. Dosing it may be what caused my b/g algae.


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## dwalstad (Apr 14, 2006)

Weaveman, you have made my day!

The trick with controlling algae is to play on any advantages that plants might have over algae. Iron in the substrate v. the water is one of them. CO2 in the air (aerial advantage of floating and emergent plants) is another. 

For a successful NPT, have lots of plants and promote their advantages over algae.


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## ekr (Jun 21, 2020)

I just gave this discussion a quick scan and didn't saw this mentioned:

I clean cyanos with a very strong siphon. It's a very girthy length of stainless steel (from a random brick&mortar store, not aquarium related), fixed to an even wider piece of garden hose. No silly plastic contraption, full unrestricted flow. It fills up a 20l canister in about 1-2 minutes or so.

If I'm not using it to cleanly pull out old sand or soil that wants replacing, or to decimate Java Moss explosions, I can easily draw BGA off leafs with that. For thin stem plants (rotalla etc.) I just suck the whole plant in - healthy ones will have strong enough roots to survive this procedure, and then all BGAs are totally gone. Larger plants need more care due to large leaves creating a Delta-P effect, hard to let go off without ripping it or the whole plant out. But often it's good enough to hover a cm or two away, the current often does it.

Best of luck! This, too, will pass, if you find the right concentration of all the various nutrients and light...


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## dwalstad (Apr 14, 2006)

Manual removal like this is always a good tool for fighting algae.

During tank cleanups, I often remove clumps of matt algae.


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## shudaizi (Jun 9, 2020)

So even though I gave a bit of an account in another algae thread, I thought I'd post an official update to my own thread from late summer.

We switched to distilled water (but supplemented with Diana's water hardening recipe as we were doing already with our tap water as we're on the same, super soft, reservoir that supplies NYC) and did, indeed, see our phosphates drop into the sub-2ppm range. But, it didn't seem to really make much difference: the BGA was still persistent. We ordered and put in some Red-root Floaters and they just didn't seem to do well, barely hung on. Soon, a different kind of algae also showed up, green slimy fibers (different from the green hair algae that would show up later), that tangled all over the RRF roots. The BGA started coating the RRF leaves.

We put a UV sterilizer in and that only seemed to keep the BGA from getting worse, but really didn't end it either.

So we started doing very frequent (every other day!) water changes (about 4 liters out of 28 liters per time). Manually scraping off all the BGA, siphoning it out, then using a fine mesh net to net all the floating stuff afterwards.

It was a lot of work and quite discouraging. And that went on for about two months. We noticed some new snails, the small type that look like ramshorn but with the shell that lays flat instead of going upwards. And then we noticed some daphnia (or something similar). And shortly thereafter, the BGA got less, and came back less and less after water changes. So, we started lengthening the time between water changes, going 3 days, then 4, then 5, then a week. Finally, it just stopped being necessary at all.

For the last two to two and a half months or so we've not done any water changes at all. Just topping off (still with distilled water) every week or so. The red-root floaters and duckweed grow well. I pull out some of the duckweed every week or so. The red-root floaters seem to go through cycles: they'll grow and look great, and then a ton of them will weaken and the old leaves die off (go transparent). Sometimes I remove those, sometimes I don't.

The other plants are all doing well. The water wisteria have gone "aerial" (which seems to correspond to when the Red-root floaters start doing less well, but I'm not 100% about this correlation yet), and I periodically cut the tops back (which seems to get the red-root floaters to go crazy) -- the pics below were taken right after trimming the water wisteria back to just above the water line (hence not visible from the camera position.

There are about a dozen different species of plants in the small tank. Some that we were certain had failed (the Valisneria) have suddenly reappeared. The pygmy sword chain is spreading. Even the dwarf hairgrass is spreading (though slowly and fairly sparsely). The crypts are gorgeous. The Ludwigia repens have gone wild (new shoots, healthy stems pushing up). The bacopa have spread too.

Livestock remains sparse: one nerite, one male betta, and the "pest" snails. We did see the one remaining MTS (the rest of the dozen MTS died) a couple of times, but who knows if he's still alive as we haven't seen him in two months now.

The BGA is completely gone, but we do get some green hair algae -- a few of the strands can get to be 12 inches or longer, and some very short "hairs" on the sides of the tank. But it all stays pretty sparse so far. I pull some out every so often, but it's not a stressful thing like the BGA was.

No heater, but we do still have the HOB filter going (very low flow, barely a trickle) -- after a decade of cichlid care, I'm perhaps nearly unable to have a tank without a filter! 

Two pics -- virtually the same except for the exposure: one is brighter to see details further back; the other is more "natural" or faithful to how the cube looks to the eye.


Jan 2021


Jan 2021 - 2

EDIT: We really don't know the cause of the change. I'm left only with the general "somehow the water changes bought the tank enough time for the tank to achieve some equilibrium and stabilize" -- what specific parameter was out of whack, I have no idea. We didn't change our feeding habits or light period or light intensity. So, basically have no idea what changed.


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## dwalstad (Apr 14, 2006)

Beautiful tank! Love the red floating plants. 

Plant growth is robust enough now to prevent algae.

In August you wrote that you were dosing the tank with iron? Are you fertilizing with iron now?


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## shudaizi (Jun 9, 2020)

Hi Diana,

I think that was someone else who was or recommended dosing with iron. I actually didn't even see that post until the other day when I finally logged back into APC after a long hiatus. We did use an aquarium fertilizer (UNS All-in-One) once or twice somewhere along the way, but it didn't seem to have much effect, so we didn't continue it. (We have a much smaller 3 gallon tank that has just plants and snails -- all the shrimp we tried putting in there died within two weeks -- and since that receives no fish food, we do dose that about once a month or so; it had just a very brief bout (one or two weeks) with BGA and has been algae-free.) From your posts above, I'd consider iron tabs for sure, but we haven't tried it thus far.



dwalstad said:


> Beautiful tank! Love the red floating plants.
> 
> Plant growth is robust enough now to prevent algae.
> 
> In August you wrote that you were dosing the tank with iron? Are you fertilizing with iron now?


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