# Caution: tanks may be smaller than they appear



## MacFan (Jul 30, 2006)

I've been having issues for some time, though I follow a carefully calculated dosing scheme and always do 50% weekly water changes, I battle algae of different tpes. This week, I had my 150g spend most of the week hazy in appearance, even after a 50% water change!

The test strips I use for quick checks was making it look like there was little or no nitrates in the tank. While I found that hard to believe in some tanks, the bog on the 240 has grown in quite a bit so I was willing to believe things were out of balance.

So I pulled out the Multitest test kits I have. They're nice because they have a tray with 6 little chambers so I can test multiple tanks at once. First I started the iron test which can take up to 45min to develop full color. Then I went to phosphates and found they were 2.5-3.0... much higher than they should be. If my nitrates were truly low, that might explain the algae. On to the nitrates, and they were basically off the chart. The chart went to 50ppm and it was as dark or darker as that color!

How was this possible? I had suspected something was amiss when I recently upgraded my RO water storage tank so I could do a 50% water change on the 240g tank. I knew tanks didn't hold what they were rated for, but had previously used online calculators to estimate the tank to hold about 210g. So that means a 105g to refill after a 50% water change. The tank has volume markings on it, and looking before and after the fill, I found it was only using 80g of water. So back to the calculator today. The tank is 72x30x25 but if I measure from the top of the substrate to the water line, it's only about 19.5" and the half inch glass subtracts an inch off each side dimension. So the tank is actually only 71x29x19.5 which calculates to 173.8 gallons. This particular tank has a big stack of rock and several large pieces of driftwood. So 160 gallons is actually quite reasonable.

I determined my 150g tank to be closer to 95g, my 72 and 60g tanks to be closer to 50-55g and my 15 and 20g tanks to be 10 and 15g. The estimative index dosing charts put 10-20g together in one range, so my small breeding tanks were the only ones I was actually dosing properly!

According to my favorite reference (http://www.finostrom.com.gr/images/aqua/fertilizers/map.htm) on nutrients, this would explain why I was seeing signs of Calcium and Magnesium deficiency. I'm adding it to reconstitute my RO water and thought it must be being consumed. But a high imbalance of Potassium can cause a deficiency in those elements and cause distorted, cupped leaves and slow/stunted growth!

So I did my 50% water change today, I figure that will put the levels down to almost what they really should be. I will skip the first two days of dosing this week to allow it to consume a little more, then resume at the revised numbers. Perhaps I will hold off on adding the Potassium Sulfate for now too. It's an optional component of EI, saying you could add it if you had a high fish load. It was included in Barr's GH Booster when I used to use it, and the time one of my tanks looked the best was when I was doing daily water changes to raise discus fry. As a result, I was adding GH Booster daily and because the plants did so well, I theorized the extra Potassium was the key factor. In reality, it was probably the lower overall concentration of nutrients since I added those daily and the 50% water change the following day kept it from building up.

Sounds good in theory anyway... I guess we'll see!

Michael


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## Tex Gal (Nov 1, 2007)

This can be so complicated, even with EI. All that work and multiple kits. Makes you wonder which kits to believe. So how did you decide?


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## kimcadmus (Nov 23, 2008)

Hi MIchael,

Yes the tank volume issue can be tricky especially when measuring ferts. Is there CO2 on the big tank?
I'm trying to remember what plants you had in the large tank. I remember mosses, ferns, anubias and several types of stems , right?

I experimented with EI in one of my tanks and have to say I had to experiment alot to control algae. After I eliminated lighting and co2 issues I would tweek the ferts. Most of my issues had to do with nitrogen depletion then small amounts of bba would show up. I had a period of time when I had staghorn which as I understand it some call hell algae. It was growing not only on the plants but the substrate. I use pps-pro on my other tanks and found the algae issues to be fewer, slower, and easier to control give my lighting, co2 etc.


I can certainly emphathize with you. Any pics of the various algaes?


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## Newt (Apr 1, 2004)

My 75 Oceanic Systems tank volume is only 75 gals when measured on the outside. When you take the dimensions on the inside its more like 71.6 gals. When I first filled the tank after adding substrate and other decorations I added a 1/2" wide piece of masking tape along the back edge. As I filled it I marked off each gallon. I have 66 gals which includes my filter (and some of that water is 'locked' in the substrate). So when I dose I use that number. When I calc my light levels I base it on what I call 'Open' water - the amount of water that does not include the 2 gals in my filter and about 2 -3 gals in the substrate.


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## MacFan (Jul 30, 2006)

I agree, test kits are a pain and it's hard to know when they are accurate (whether the kit or due to human error.) That's one of the reasons I like EI is you can get away from that in general by knowing what you're adding to a given volume of water and "resetting" it with your weekly water change. 

Ultimately, the most telling factor to me is that I could do more than 50% water changes and not come close to using the 100+ gallons of water I think it should take for a 240g tank. That moved my dosing from 2 x 100-120g category to 2x 60-80g category which reduces Potassium Nitrate from 1 Tbsp to 1 1/2 tsp (half a Tbsp) and Phosphate from 1 tsp to 3/8 tsp (less than half). The only tanks it didn't change the dosing for was the breeding tanks. Those tanks are also overgrown in general as they function more as growout tanks. 

In terms of plant symptoms.. 

- Altalenthera Rosefolia used to grow like a weed in my 240. I would have to cut it back at least once a week to keep it from growing out the top of the tank. But after a BBA outbreak, I planted small plantlets of it and they're still maybe 3" tall after months. (slow, stunted growth)

- Hemigraphis traian was growing with leaves curled/cupped downward which is a sign of calcium deficiency. I responded by increasing my GH which helped, but apparently a potassium excess can cause a calcium deficiency and it's quite reasonable to think I had a potassium excess. 

In addition, I was getting diatom/brown algae in my 240g. That should only happen on new immature tanks that have an excess of nutrients. And as I mentioned, I was getting hazy water in my 150g, typically a sign of bacterial bloom. At first I said it was because I replaced some bio media in my filter, and typically it goes away once it has consumed the excess nutrients. But it persisted for more than a week despite a significant mid-week water change. 

The signs were there... it was just hard to know what to make of them. I think I'm on the right track though, so I guess we'll see. 

Michael


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## MacFan (Jul 30, 2006)

Ok, this is getting ridiculous... I cut my dosing in half at the start of this thread. Now after 2 weeks of following that closely. Below are the test results. I have no idea how to interpret this... my 60 and 72g tanks are doing pretty well overall. The 150g is coming back nicely. And the 240 is a disaster, with persistent diatom (brown) algae, and a re-occurrence of BGA. Diatom algae is typically associated with new tanks and an excess of nutrients, while BGA is supposedly a sign of low nitrates. Since nitrates are the dominant nutrient, how can both be true? I'm pouring CO2 into all the tanks at high rate. The 240 sees a 1 point pH change between the overnight high of 7.4 and the daytime low of 6.35 due to CO2 injection. I don't have a meter on any of the other tanks anymore so I don't know what they are doing. All tanks have high circulation. I use RO water reconstituted to a GH/KH of 4-5.

The unlabeled cell in the test is one of my 20g tanks with cherry shrimp. It exploded with growth initially and is doing ok now but not the insane growth I saw initially. It has CO2 but I have no idea how much, probably not what it should be.

Since the 240 is in such poor shape, I could understand it testing high, but the tanks that have tons of growth have nearly the same amount. How can that be?

If I go to dosing twice a week, do I do Sun/Mon and Wed/Thurs with water changes occurring on the weekend?


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## northtexasfossilguy (Mar 6, 2009)

Honestly, you should just break down and buy a UV filter. I got one with a tank that I bought on craigslist, cleaned it up and now my green water is so clear it doesn't look like there's even water in there. It looks great, it added a little more stirring, and I positioned it to force the current to blow my CO2 bubbles downward and they stay down in the water column now until they are almost totally dissolved. I'm kinda leery about killing everything in the water too, but at least I can see through my tank again.


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## northtexasfossilguy (Mar 6, 2009)

What kind of substrate does the 240g have? I mean it sounds like it could be fertilizer or the ferts you are adding are causing this...


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## MacFan (Jul 30, 2006)

Last weekend, I moved the fish to clean storage bins with tank water and air stones for the day, and tore the tank down completely. I had been wanting to replace the substrate anyway, so this was a good excuse. I vacuumed every last bit of detrious out of it and reset it. I was inspired by a tank picture in "The Inspired Aqurium" (Mike & Jeff Senske) that had discus and a heavy load of crypts, anubias and other long flowing plants. I've moved almost all the crypts I own into that tank, along with some other plants and it looks good and so far has been going well. I've also been dosing 2/3 the fertilizer level I calculated, but once things are going well, I might bump it back up. It occurred to me that those dosages are for _heavily_ planted tanks, and that tank in particular had lost a lot of plant load. All that's left now is my 60g tank which has great looking plants but a bad infestation of BBA. This weekend I'll probably switch out the substrate and take care of the BBA. That will leave only some of my small breeding tanks with severe BBA problems, but those tanks are less important plant-wise. 

Michael


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## supersmirky (Oct 22, 2008)

Well, I have a ton of crypts if you need some!


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