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Nitrate problem.

6K views 62 replies 14 participants last post by  Vpaw 
#1 ·
So in my 20 gallon planted I've always had really high nitrates. Either 80 or off the charts. I once did 50% daily changes for a week to get them down! and it worked! for a little bit. Back the I. Used a bucket though. Now with my python it's no big deal. I use API liquid testing.

Info:
Black sand substrate
All live plants
Sponge filter with air stone
7 Cory cats, 2 platy's, 2 ADF( moving soon), 1 apple snail, 2 ott's, 10 cherry shrimp
Special plant light
Root tabs
Fluorite mixed into the substrate
Weekly seachem fertilizer after water changes.
25-40% weekly water change
Ph: 7.8 (can't get it down :()
Gh: 11
Kh: 15
Ammonia: .25
Nitrite: 0


Aren't plants supposed to take up nitrates? Why are they so bad? How can I fix it?
 
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#40 ·
Ask yourself:
When the shrimp eat something (dead or dying plant) are they REMOVING nitrogen?
Or just changing its form?

Answer: They are turning plant-mass into shrimp-poop-mass.
This is not removing N from the system.

If I take a dead skunk out of the bedroom and move it to the living room will the house be cleaner?
---------------------------------------------------------

pH problem:
pH is not a stand alone value.
Many things in an aquarium can try to control the pH.
The most common things are:
Carbonates and bicarbonates. Tested with the KH test.
If the KH is high the pH tends to be high and hard to change.
If the KH is low the pH will be controlled by something else, and is usually easier to control (depending on what the other things are)
Sources of KH: The tap water (especially well water, whether supplied by a private well or a public water company).
Substrate or decor that is limestone or any similar type of rock (Calcite, Marble, Dolomite...) Sea shells, coral, oyster shell grit. These materials decompose, adding calcium and magnesium carbonates to the water.
KH raising products that often contain sodium bicarbonate (Baking soda) or potassium bicarbonate.

Organic matter such as peat moss, driftwood, and leaves such as oak or Indian almond leaves. These materials generate organic acids. Sometimes they can behave like a sodium exchange water softener, taking positive ions out of the water and adding H+. The pH usually goes down unless the KH is so high that it removes the acidic materials as fast as they are generated.

Water companies may add materials that we have no test for. For example my tap water has sodium hydroxide added to keep the pH up. Acidic water damages the pipes.

I would test your water will all the tests before and after (ie: tap and tank) and get a water quality report from the water company. If this does not track down why the pH is rising then start testing everything in the tank this way:
Put a small amount of each rock, gravel, sand, and all water additives into separate jars and add some water. Test the GH, KH, TDS and pH when you start, then every few days until you see a change in these values.
 
#41 ·
Diana- yes I know my kh is very high, my gh is at about 16 last time I tested (long time ago) and kh is 10 (I think) I have drift wood in all my tanks, no shells. I vaccum out the poop as far as I know though. My shrimp amount is significantly decreasing for some reason :(
 
#44 ·
I had super high nitrites from a long period of insufficient filter and tank maintenance ... Long story short, I did 25-30% water changes daily, with vacuuming of substrate, plus I rinsed all the canister filter media several times in dechlorinated water to get all the gunk out. Took 1-2 weeks to get nitrates down under 10%.

Filter media and substrates can hold a lot of crap, and as it decays it's just continuing to produce ammonia which is converted to nitrites then nitrates.

Good luck with your tank and let us know how it goes.
 
#51 ·
Sorry to post in my old thread but I would like to say that I finally fixed the nitrate problem! I'm surprised no one mentioned it earlier... I tested my tap water, which I have done for nitrates but they wanted ammonia and nitrite as well. Turns out he ammonia was high and all I had to do was switch to prime conditioner! I've been using it for about a month now.
5 gallon: 5 ppm
20 gallon: 20 ppm
30 gallon: 10 ppm
65 gallon: 5 ppm

Now that stuff can actually life in there and not die (plant-wise) I can get good plants! I added some baby tears and hornwort. They seem to be doing very well.

Now if only I could lower that ph...
 
#52 ·
Glad you got to the bottom of that.
Should I mention: Prime locks up nitrate, too.

What pH problem?
Post the following:
A) Tap water right out of the tap. pH, GH, KH, TDS (if you have a meter)
B) Tap water that has sat out 24-48 hours. pH, GH, KH, TDS
C) Tank water right before a water change. pH, GH, KH, TDS
D) (Not a test) tell us everything you add to or do to the water to prepare it for a water change.

What these will tell us is mostly comparing one to another:
A compared to B: If your tap water pH changes then it could be gaining or losing CO2. This takes several hours to happen, so waiting at least overnight is important, though if you can stir the water several times the change can happen faster.

B compared to C. B is what your tank ought to read. If B and C are different, then there is something in the tank affecting the pH.

D will tell us if something you are adding to the tank might be altering the pH (if B and C are different) pH altering materials are an obvious culprit, but KH altering products will also change the pH.

Last test (this might take a couple of days) will tell us if something in the tank is altering the pH. Do this if B and C tests are different:
Put a sample of everything in the tank into a separate jar of water.
A handful of substrate, a chip off the rock, the bits you trimmed of the driftwood, and so on.
Test GH, KH, TDS and pH after a few days. Compare these tests to B (tap water after it has been sitting).
 
#53 ·
Diana-
Ok no problem! I'll post it in a few days when the tap water sat around I guess.
Should I use conditioner on the tap? Or just leave it plain? I only have ph, gh, and kh testers.
Also you say prime locks nitrates. As in it keeps them from rising? Or from changing at all? How does it do that?
 
#54 ·
I only tested my 20 gallon aquarium, which is the planted one. If you want results from the other 3 please say so and I'll do them.

20 gallon:
Ph- 8 (I think it's getting kind of lighter)
Gh- 13-14 (lost count)
Kh- 7
Water from tap:
Ph- 8.3 (it's got purple in it but is still brown. But darker than what I usually call 8.2)
Gh- 11
Kh- 8
Tap that's been standing around:
Ph- 8.2
Gh- 12
Kh- 7

What I add:
I drain the water and then since I have a python, condition after all the water is in. If i do it before won't it not be effective? I dose Seachem prime, the correct dosage. For the 5 gallon I use some dechlorinator (don't see name of brand) and it's a green bottle with orange fish on it, I dose the water before it goes into the water.
A day after water changes I usually dose seachem flourish into the 20 gallon but I often forget, all tanks except 5 gallon have at least some driftwood. Sometimes I use root tabs but it's been a while. It has a sponge filter, I think that's pretty much it..

Note: maybe I read everything wrong but the shades do tent to change and I don't see much of a difference on chart... Am I supposed to look at the areas that are dark or where the light touches?

Note2: I don't follow the rules 100% on kh and gh, I add a few drops at a time until I get 3 away from my usual reading then I do one at a time then invert, it takes too long otherwise, does this alter results?
 
#55 ·
Test method: Does not alter the results to add several drops and shake, then just add one drop at a time as you get near the end.

Tap water fresh and sitting around show no major difference. The differences reported are within the error of the test.
Tank GH is significantly higher, so suggests that something is adding calcium or magnesium (or both) to the water. Check the fertilizers, perhaps the root tablets. When you figure it out, stop adding this product.

Here is my take on this pH situation:
7 Cory cats, Usually soft water fish, but the common ones are not very picky. The difficult ones do prefer softer, acidic (or neutral) water.
2 platy's, Hard water fish, but bred in captivity so long they handle a wide range of conditions.
2 ADF( moving soon), (Don't know about frogs)
1 apple snail, Needs hard, alkaline water or else the shell will erode
2 ott's, Soft, acidic to neutral water.
10 cherry shrimp I think RCS are among the more adaptable of shrimp, though perhaps somewhat lower pH and GH might be better.

So...
You have livestock that likes the water it is in.
And you have livestock that would prefer softer water (lower GH).
a) Do nothing, they are alive.
b) Separate the livestock and do the work that is involved in lowering the GH, KH and pH for the critters that come from soft, acidic water.
c) Return the soft water livestock to the store, just keep fish and shrimp that like your conditions.
 
#56 ·
That's good to hear about the test. Thank you.

Oops, that is an older stock. Currently I have:
4 ottos
2 plattys
6 Cory cats (albino, pepper, emerald, Julie, and the like)
3 nerite snails
Red cherry shrimp
Betta
And the live plants, don't live plants like soft water?

Root tabs:
Calcium- 14.9%
Magnesium- .06%

So it's pretty high on calcium. I should post results from other tanks too then. I have a few soft water fish...

5 gallon:
2 african dwarf frogs and nerite snail. Also my quarantine tank. I don't think they need a change or test really.

30 gallon:
Bs pleco
Harlequin rasboras
Zebra danios
Gold barbs
3 Dwarf rainbow fish

65 gallon:
2 angelfish (they're not really growing well and the pinoy isn't turning blue)
6 black skirt tetras
1 red tailed black shark
4 nerite snails
Some trumpet snails
1 dwarf gourami
2 mollies (that I'll probably rehome soon but they are good for my water..)
 
#60 ·
OK, alternate solution:

Some plants can utilize carbonates as a substitute for CO2. (about half the plants we use in aquariums can do this)

Topping off the tanks with tap water constantly adds all the minerals etc that are in the tap water (including GH and KH) while just the water evaporates.
While it is true that the plants also use Ca and Mg (the minerals measured as GH) they use more carbonates when that is the only source of carbon.
So the GH rises, but KH does not.
 
#62 ·
There may not be a single answer.

Here are some more tests:
Take a bit of each thing from the tanks and put each thing in a separate glass or jar of water. Measure the GH, KH, pH every few days and see what changes.
Substrate
Rock
Driftwood
Ceramic merperson
Fertilizer
other additives (one per jar)
other.
Compare to the tap water tests done earlier.

You might not have to test everything.
Start with the things that are most suspicious.
Fertilizer tablet
Stone
 
#63 ·
XD that sounds so tedious... He only things they really have in common is

driftwood (which SHOULD be doing the opposite effect)
Some rocks
Heater
Air stone
That's it..

So is there a way to lower it? More driftwood? Should I buy peat moss? Certain plants?
 
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