# [Wet Thumb Forum]-What are "ideal ratios"?



## Lois (Jul 28, 2003)

Could anyone explain to me in layman's terms what ideal ratios are for macro & micro neutrients? I've been browsing different posts and came across info about N ratios, K:N ratios, and Redfield ratios (whatever that is). I've always understood that No3 should be kept around 5ppm, Iron and phosphate to be kept at 1, and to dose plenty of K in order to keep plants growing. This seems easy enough to follow for me. What has me confused are these ratios. How do you determine how much of a certain nutrient to add to your tank? I know test kits measure ppm but when adding liquid ferts to my tank I use ml and Im at a loss to how to convert that. Do you just add nutrients until the test reveals you have that much ppm in you tank or is there some way your suppose to calculate each nutrient per gallons of tank water? Also I've found test kits (esp. Nitrate & Phosphate) to be very unreliable. 
I've seen Chucks Gadd's calculation page which helps some but I'm still confused about all the other nutrients not listed and their ratios.

How do you tell how much calcium is in your tank? Since my plants arent forming roots well& some seem stunted in growth I thought this could be the cause. Then I read that high doses of K could cause plants to show potassium difficiency. I was adding K2so4 by disolving 2Tbls in 300 ml of wtr. I added 5-10 ml a day trying to bring down my nitrates (which register 10ppm on my AP test) and to try to resolve pinholes in my Hygro P. This didn't work for either problem. Now I have brown cottony fuzz balls forming on my plants along with hair and green algae. I have diy yeast injectors but my tanks always struggling with algae. The plant roots don't seem to be growing well and red plants are stunted and greenish looking. I read Karen Randalls artical about plant nutrition on Aquatic Horticulture which seems to go against everything I've ever read about having healthy plants. 

I would really appreciate any info as well as links to sites further explaining this ratio confusion. Iv'e spent long hours trying to find these for myself and frankly am tired and frustrated. 

If someone could also explain a way to bring down my Nitrate without adding anymore K2so4 I'd be grateful.

My tank is 55 gal with 4 40w flourescent bulbs
N=10-20 (depending how much K2s04 is added)
P=1
Kh=6
gh=10-15 (AP test shows such gradual change its hard to tell)
Fe=1
Thanks, Lois


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## Lois (Jul 28, 2003)

Could anyone explain to me in layman's terms what ideal ratios are for macro & micro neutrients? I've been browsing different posts and came across info about N ratios, K:N ratios, and Redfield ratios (whatever that is). I've always understood that No3 should be kept around 5ppm, Iron and phosphate to be kept at 1, and to dose plenty of K in order to keep plants growing. This seems easy enough to follow for me. What has me confused are these ratios. How do you determine how much of a certain nutrient to add to your tank? I know test kits measure ppm but when adding liquid ferts to my tank I use ml and Im at a loss to how to convert that. Do you just add nutrients until the test reveals you have that much ppm in you tank or is there some way your suppose to calculate each nutrient per gallons of tank water? Also I've found test kits (esp. Nitrate & Phosphate) to be very unreliable. 
I've seen Chucks Gadd's calculation page which helps some but I'm still confused about all the other nutrients not listed and their ratios.

How do you tell how much calcium is in your tank? Since my plants arent forming roots well& some seem stunted in growth I thought this could be the cause. Then I read that high doses of K could cause plants to show potassium difficiency. I was adding K2so4 by disolving 2Tbls in 300 ml of wtr. I added 5-10 ml a day trying to bring down my nitrates (which register 10ppm on my AP test) and to try to resolve pinholes in my Hygro P. This didn't work for either problem. Now I have brown cottony fuzz balls forming on my plants along with hair and green algae. I have diy yeast injectors but my tanks always struggling with algae. The plant roots don't seem to be growing well and red plants are stunted and greenish looking. I read Karen Randalls artical about plant nutrition on Aquatic Horticulture which seems to go against everything I've ever read about having healthy plants. 

I would really appreciate any info as well as links to sites further explaining this ratio confusion. Iv'e spent long hours trying to find these for myself and frankly am tired and frustrated. 

If someone could also explain a way to bring down my Nitrate without adding anymore K2so4 I'd be grateful.

My tank is 55 gal with 4 40w flourescent bulbs
N=10-20 (depending how much K2s04 is added)
P=1
Kh=6
gh=10-15 (AP test shows such gradual change its hard to tell)
Fe=1
Thanks, Lois


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## Rex Grigg (Jan 22, 2004)

I don't worry about ratios. I just try and keep my levels as such:

Nitrates 5-10 ppm
Phosphates 0.5-1.0 ppm
Iron 0.1-0.3 ppm
Potassium 10-20 ppm
CO2 15-25 ppm

I dose KNO3 and K2SO4 dry. To use Chuck's calculator to figure this use 1 ml as the amount of water.

You should not have any problems with an AP gH test kit. The color change is quite dramatic. Make sure you shake the tube well between each drop. With a gH of 10 or more you should not be short of calcium.

I'm betting that your DIY CO2 is not injecting enough CO2 into your tank. On a 55 gallon tank DIY become more of a if than anything else.










American by birth, Marine by the grace of God! This post spell checked with IESpell available at http://www.iespell.com

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## Lois (Jul 28, 2003)

I've been keeping my levels at what you suggest but still have algae. At present I have 2 co2 injectors working changing them at different times during the month to assure there's always co2 in the water. (I just don't have the money for and auto system) I hoped understanding Redfield and other ratios I might be able to fine tune my dosing. Would you know of any links I could look up?


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## mm12463 (Mar 5, 2004)

VisitChuck's page.

It helped me a lot. How long ago did you setup the tank. I think from reading a lot of stuff on these boards it is apparent that a newer tank is susceptible to algae. Sort of a break in period. I have just started to over come my algae problem from a tank I started up in late October. I think my lack of knowledge and too much organic waste was my big issue.

Read Chuck's articles they are pretty helpful. Although I don't use the power chemicals it helped explain a lot to me.

Mike
http://fish.silver-fox.us


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## Lois (Jul 28, 2003)

I've had my tank for about 3 years but just overhauld it early September because my phosphates were out of control due to pond tabs added to the substrate. I read a post that adding nutrients to the substrate keep unwanted ones out of the water column. It didn't. I just get confused with all the conflicting things I've read. 

Right now I'm trying to understand how to bring down my N03 levels w/o adding too much K. After reading a post from Roger, I understand excess K causes symptoms resembling calcium deficiency. If that is true, maybe my stunted plants & lack of root development is because of too much K. I also read so4 isn't used by plants that much. If I'm adding 5-10 ml a day to my tank along with mgso4 wouln't that cause problems as well?


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## Lois (Jul 28, 2003)

Mike,
Thanks for the link. I visited it and it looks informative. I'll make some copies to keep in my files.


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## mm12463 (Mar 5, 2004)

I guess some more experience people should really answer this. But I will give it a shot.

Added more K2S04 I don't think will bring your NO3 down. Least not in a direct correlation. Maybe in time the plants will use it. But by then you could have bigger issues.

I think your best bet to remove the high amount of NO3 is to do some water changes maybe over the period of a few days. Get your water basically down to a fresh level and do some tests. Then start your dosing.

But I'm not an expert. Not like a lot of the people here so please take my comments with a grain of salt.

Mike
http://fish.silver-fox.us


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## mm12463 (Mar 5, 2004)

Oops one thing that helped me was to do this. I had the same problem as you. I was added 1mL of whatever. But I didn't get how that correlated with the mg/L in the tank.

So I did this.

1 gallon = 3.7583 liters
55 gallons = 206.7065 liters

So if you have say a fertilizer that has 4.36 mg of NO3 per mL you do this.

4.36/206.7065 = 0.021 mg/L will be added to the tank. Keeping in mind mg/L equals ppm.

I dunno. It helped be understand when I add 1 ml of whatever to the tank I will end up with X mg/L or ppm.

And of course you have to take in effect how much is already in your tank with your water tests.

Mike
http://fish.silver-fox.us


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## Lois (Jul 28, 2003)

Mike,
Thanks for all your help. I think I'll try your formula out when I try keeping the ratios for my tank.

Lois


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## Roger Miller (Jun 19, 2004)

Lois,

A disorganized bunch of questions and comments follows...

What is your water change schedule? Your K2SO4 dosing comes out to 10-20 ppm/week according to Chuck's calculator. If you are using small water changes then the K levels might get pretty high after a while.

Your GH is high enough that you shouldn't have to worry about magnesium or calcium deficiency.

Sulfate is used by plants in only small quantities, but I'm not aware of any problems related to high sulfate levels.

Where is the nitrate coming from?

I don't worry too much about ratios. It might be possible to set up "ideal" nutrient ratios for a specific plant, or for a specific phase in the life of a specific plant. For a community of plants that would be more difficult. Our plants have several sources of nutrients, including nutrients in the water we use for changes and nutrients in fish food. The relative importance of the different sources of nutrients varies from tank to tank. In general the nutrient ratio that the plant gets and the nutrient ratio that you dose with fertilizers are always different ratios.

Sears and Conlin pointed out some time ago that the dose you use in your tank needs to be tailored for your tank. There is no ideal. You need to start with some reasonable advise and experiment a little. While experimenting you need to be sure not to increase nutrient doses beyond the point of diminishing returns. That is a difficult call to make.

As a last note, you almost certainly don't need 1 ppm of iron in your water.

Roger Miller

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_"The indispensible first step to getting the things you want out of life is this: Decide what you want" -- Ben Stein_


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## Lois (Jul 28, 2003)

Roger,
I appreciate your advice. I've had good success with my plants and tank following Sears & Conlins advise for PMDD system adding the ingredients seperately rather than together. After doing well for about a 2 years though, the system hasn't worked for me any more. Along with new types of algae, my red plants such as Rotala Macandra, Red Tiger Lotus and Alternanthera Roseafola have all turned a greenish color from the beautiful red that they were before. Everything seems to have underdeveloped roots.

I don't know why my No3 keeps going up. According to my AP test kit, my tap water shows 20 ppm (the water company said it should be 10). My kit is new but may be off. I struggle to keep my tank water at 10 by adding extra K2so4. I'm afraid of adding too much K though. 

I do 1/4 water changes 2x a week because if I go longer the tank looks worse.

I'm not absolutly sure about my GH readings. My AP GH kit is quite old and I'm thinking I need to replace it since I have so much trouble seeing a color change. I did read a comment that when testing for GH its hard to tell whether the levels are coming from Magnesium or Calcium since the kit doesn't break that down. That's why I began thinking I might have a Calcium deficiency since I've always added Mgso4 with my PMDD.

Because of underdeveloped roots I finally decided to try adding CaNo, thinking there was a calcium deficiency. Now I see a slight reddening in my plants and they seem to be developing new roots but my tank water is all green now. I'm assuming it's from the extra N. 

You said:
"You almost certainly don't need 1 ppm of iron in your water".

Are you suggesting I might be keeping my iron levels too high? Everything I've read states this is ideal. Please explain.

Lois


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## Roger Miller (Jun 19, 2004)

Lois,

Something is wrong. Given the numbers that you report your tanks should have no major nutrient shortages. You don't need to fine-tune ratios. One possibility is that one or more of the test results or estimates is wrong. Another is that the problem is not caused by nutrients. Lighting and damage by fish are two other possible causes of problems.

Incidentally, what do you use to add nitrate and trace elements?

1 ppm iron is way more iron than any plant needs on a regular basis. Iron is a *trace* nutrient. It is needed in trace amounts. The old scuttlebut about how much iron to dose to a tank was based more on how much iron *could* be dosed before problems appeared and far less on how much iron needed to be dosed for healthy plants.

Diana Walstad's book "Ecology of the Planted Aquarium" is a great source of information on the behavior of iron in aquariums. I've posted (over and over) about iron chemistry, problems with test kits, deficiency problems and related issues. Look in the "El Natural" forum for a recent thread.

My hat is off to Sears and Conlin. Their papers are a landmark. But I have two problems with their approach.

First is that in the long run you can't use nutrient deficiency to regulate growth in an aquarium -- certainly not with a major nutrient like phosphorus. If it works at all then ultimately the tank will run out of that nutrient and plants will suffer deficiency. Even Paul Sears has said that he eventually had to start adding phosphate to his tanks.

Second is the emphasis on iron and iron testing. The emphasis on iron is entirely unrealistic. The symptoms of iron deficiency are non-diagnostic; iron test kits produce substantially meaningless results; the levels that people believe they *must* maintain are far out of line with the nutrient requirements of plants. There are other problems.

Roger Miller

------------
_"The indispensible first step to getting the things you want out of life is this: Decide what you want" -- Ben Stein_


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## Hispid (Feb 3, 2005)

I'd just go back to what Rex said first up. Monitor your CO2. I'm willing to bet your not getting enough or it is not stable enough. If you have accurate pH and KH test kits use the chart on the Krib siite to work out your CO2. Test it in the morning and again at the evening to see what the swing is. Test it when you first put on a new bottle and again before you change the bottle. The most likely source of problems is CO2 if you are dosing and doing 50% weekly water changes everything else should be fine. Look to the CO2.

Cheers Tony


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## imported_Art_Giacosa (Nov 29, 2003)

Lois,

Can you elaborate on your substrate? I've run into similar problems in the past when a substrate either compacts, becomes anaerobic or has a nutrient imbalance.

Regards,

Art


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## Lois (Jul 28, 2003)

Art,
My substrate was a concern for me too so I just changed it this past spring. Therefore it is relatively new. I did well previously with Substrate Gold (I think that's the name of it) which is a clay that was mixed in the bottom 1/2 of my substrate along with Pure Laterite and regular sized aquarium gravel. The top 1/2 was just plain aquarium gravel. Plants grew very well. Anything I put in the tank seemed to flourish. Therefore I used the same method for my newer set-up. 

When my problems began (last summer), we had a major drought and our water co. began getting water from another dam. When I realized this I called them to see if anything was different. They said they made sure all the water had the same chemistry as before so nothing was different. I felt they probably added more buffers to the water though to reach a Ph of 7.5 then they previously needed to from our old water source. My reasoning was that I had a harder time keeping my levels at 6.8 using Acid buffer (for my discus) & within a day or so Ph would shoot back up. I finally just gave up and now keep them at 7.5.

Now, even though everything should be back to normal, my tank is still messed up. 

If I could do anything differently, I'd probably not use the clay in my substrate. Clay has a terrible tendency to cloud up the tank, especially when your rearranging plants. I found I actually had to put a layer of sand on top of my substrate because the gravel wasn't fine enough to prevent the clay from leaking into the water when I first set it up. If using to much it also becomes dense and makes it easier for compaction and anaerobic spots to form. Pure Laterite on the other hand is in granular form and doesn't seem to pose the problems that clay seemed to have done. Then again, I'm the one who's having all the problems so don't take this all to closely to heart!

Lois


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## Lois (Jul 28, 2003)

Roger,
Thanks for you help. I've read much on planted aquaria in the past couple of years and you definately seem to know your stuff.

I haven't needed to add nitrate for awhile since my tests show I have more than enough. When I did need to add it I used Kno3, adding enough to bring my levels to 5-10 ppm. Lately, since I thought Calcium might be deficient, I've been adding a couple granules of CaNo here and there because I don't know how to mix or add. (I'm thinking of stopping this since I have GW though and am suspecting It's because of the higher nitrate.)

Trace elements are added through a mix I bought from Homegrown Hydroponics mixed with water & added to my tank to bring my Iron level to 1 ppm. Chelated ingredients are:

Iron-7.0%
Maganese-2.0
Zinc- .4
Copper-.10
Boron-1.3
Molybdenum-.06

Lois


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## Roger Miller (Jun 19, 2004)

Lois, reading your reply to Art and going back over your earlier posts has left me wondering.

Do you currently have a pH of 7.5 and KH of 6 in the tank you're asking about? In this tank, did you previously use an acid buffer to lower the pH? When you said that plants did better with water changes twice a week, was this while you were still using the acid buffer, or after you stopped?

If the tank does have a pH of 7.5 and KH of 6, then the CO2 concentration is only 6-7 ppm. That isn't very high. When you were using the acid buffer that buffer reacted with the KH in your tap water to produce additional CO2. The more often you used it, the more CO2 would be produced. It isn't possible to say how much CO2 the plants got from the buffer because the presence of the buffer invalidates the KH-pH-CO2 relationship.

If all my suppositions are right, then when you stopped using the acid buffer you also reduced the CO2 supply for the plants. That by itself might explain the changes you saw in your tank. In that case you could go back to using the acid buffer or you could do something to get a better CO2 supply. Maybe you could even stop doing water changes twice a week.

Roger Miller

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_"The indispensible first step to getting the things you want out of life is this: Decide what you want" -- Ben Stein_

[This message was edited by Roger Miller on Tue December 02 2003 at 09:43 AM.]


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## Hispid (Feb 3, 2005)

What sort of reactor are you using for CO2? I know from my own experience I was getting next to no CO2 into my water until I got an efficient reactor. This solved 90% of my problems without having to move to pressurised CO2 or changing anythng else much.

Cheers Tony


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## Lois (Jul 28, 2003)

Thanks for everyone's input

I am currently using a yeast mix to inject co2 into the tank. Inside the tank I have a container which catches the bubbles to slowly allow them to dissolve. When I see the co2 in the container being used faster than the bubbles can fill it, I change the mixture. Along w/ this I also have a second yeast mixture going into the tank w/o a reactor just to make sure I always have a supply going into the tank. These are usually changed at seperate times each month.

Currently my pH is 7.5-7.6 in the tank. I haven't used Acid Buffer for about 6 mos. or so because of the pH swings.

Iv'e done water changes twice a week since before I was having any problems because my discus seemed happier with that arrangement. Now, it's also because of the tank having a general dirty appearance with all the algae problems going on.
I have looked into getting an auto. co2 injector but the few I've seen were more than I can afford right now.

Is it possible that I just need to go out and buy some new KH & GH test kits? Iv'e had them for as long as Iv'e owned my tank. Iv'e been thinking of doing this anyway but just haven't had a chance. Maybe today I hope. 

Lois


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## Lois (Jul 28, 2003)

O.k.

I just retested my tanks KH and it now shows 7. Tap water is still 6. My 2nd co2 injector is running low & is in need of a change.

As I stated before, GH is very hard for me to pinpoint because of being unable to see a color change. I added 20 drops (each one showing such a slight tinge darker that I'm finding myself very unsure of the results). I'm definately getting a new kit. Especially since Rex says Aquarium Pharm. color change is quite clear.

Tank was due for a cleaning yesterday but I was unable to do it. I'll get to it today. 

Hope this answers some questions.

Lois


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## anonapersona (Mar 11, 2004)

What temperature are you keeping in that tank?


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## Lois (Jul 28, 2003)

Hi guys

I went all over creation yesterday looking for a LFS who supplied a GH kit. The only test kit I could find w/o having to buy a super-kit with all the tests I already have is a quick dip kit. I heard these aren't accurate so I didn't buy one. I asked the employee at PetsMart if she could tell me the GH of our local tap water and she said it tested hard at 150!? or more. Until I have a chace to go elsewhere and purchase a kit of my own I decided to call my water co. to find out their analysis. 

According to them my tap water should be:
N=10ppm
GH=50ppm
Mg=.01ppm
Ca=16ppm
pH=7.5

I realize I also need to know what my tank water analysis is but at least this is a start. Except for the GH I think everything I've tested for so far (see above replies) is relatively accurate. I do have a heavily planted tank with a little over 3 wpg; water temp is kept at 83.

Now, based on Chucks calculator, my Magnesium should be 5-10ppm so I should be adding quite alot if I'm not mistaken. The problem is when I was adding more through Mgso4, I noticed spot algae. Could this be from the so4 added from epsom salts and K2so4? 

Also, I'm not sure how much calcium I should have in the water. I can't do anything about what's already supplied in the tap water. If adding so much Magnesium for the plants, wouldn't I be eventually causing the tank water to become too hard combined with the calcium?

I did my water change yesterday adding only trace elements and K2so4. Water is still green, plants have poor root developement, and red plants are still green. (Some change was noted in growth and reddening of plants when CaNo was added but very little and not w/o more green wtr).

I hope this gives you some leverage with helping me because I'm not sure what to do with this info.

One other thing, according to my phosphate kit I seem to have about .75 ppm. It has been very unreliable though.

Lois


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## Rex Grigg (Jan 22, 2004)

If your gH is 50 ppm that means it's 3 dkH. At those levels as long as you are doing regular water changes you should not have to add additional Magnesium or Calcium. All the mail order houses have gH test kits just order other supplies to help break down the shipping charge. Like this weekend it was time to order more rope perches for the birds. The mail order price on these is about 1/3 what they cost locally so I of course ordered a 6-8 month supply of perches and some fish supplies.










American by birth, Marine by the grace of God! This post spell checked with IESpell available at http://www.iespell.com

See my Profile for tank details.

See my planted tank FAQ at http://members.dsl-only.net/~rex/

[This message was edited by Rex Grigg on Fri December 05 2003 at 04:51 AM.]


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## Lois (Jul 28, 2003)

Rex,
In your response you said "you should have to add magnesuim or calcium". I'm inclined to add Mgs04, but according to Chuck Gadd's calculator it seems I would have to add alot to get the proper amount for the plants. Wouldn't this cause the GH to increase if I do this?

I'm also wondering if this may be why I have trouble keeping my nitrates down. If I remember the Sears & Conlin paper right, they stated that "monitoring nitrates is good for gereral tweeking of your formula. If nutrient X causes nitrates to drop then plants are probably deficient in nutrient X." Up until now I haven't been adding much magnesium because I thought I had plenty already supplied in the tap water.

Lois


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## Rex Grigg (Jan 22, 2004)

I noticed the error in my post. At those levels you should NOT have to add any more magnesium or calcium. I doubt a lack of magnesium or calcium is causing your nitrate problem. I think your problem is low CO2 levels. You need build or buy a reactor of some kind to get better CO2 levels.










American by birth, Marine by the grace of God! This post spell checked with IESpell available at http://www.iespell.com

See my Profile for tank details.

See my planted tank FAQ at http://members.dsl-only.net/~rex/


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## Lois (Jul 28, 2003)

I just changed my 2nd yeast mixture (I have another already going) and checked my pH levels about 12 hours later. C02 was producing continous bubbles, yet my pH was only 7.5 from a previous 7.6! I then checked my KH which previously was 6 and now found it had risen to 7. 

I read on Chuck Gadd's site that sometimes KH will go up if the bicarbonates in the tank (maybe from the substrate?) begin disolving faster due to the higher levels of co2. I just added a new substrate about 6 mos. ago. I was very careful about getting something I could use in a planted discus tank. It is just natural colored gravel for freshwater aquariums. Could it be possible that something in the gravel is doing this? I do have some snails but they dont usually grow much before their eaten by my loaches. Could their empty shells cause this to happen?

Lois


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## Hispid (Feb 3, 2005)

I don't thnk that you have a problem wth high CO2 disolving your substrate. Ignoring the changes in your pH and KH for the moment let's assume your pH is 7.6 and your KH is 7. Lookng at this chart http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html your CO2 is around 6ppm or less. You really want to be shooting for 15-25ppm. So you need to increase the amount of CO2 getting into your water. Reading between the lines of your posts it sounds like you are not using any sort of reactor, correct me if I'm wrong. In any case whatever system you are using to disolve the CO2 into the water is not working so you will need to either build or change your reactor. There are several designs to be found here http://www.thekrib.com/Plants/CO2/ and many other places on the web. Personally I'd not bother with bell or powerhead reactors and go straight to some sort of inline gas/water mixer reactor. The difference will be noticable.

Cheers Tony

[This message was edited by Hispid on Sat December 06 2003 at 03:45 AM.]


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## Lois (Jul 28, 2003)

Hispid

Thanks for the links. I've collected info on some of the reactors I'd like to make and will try to put one together today. 

Lois


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