Nitrates

[danielsaylor]

I have tested my water with the solution and test strips. Test strips says it is like 20ppm the solution says 160. Tried 2 different solutions. Changed water several times also.

[Colin_T]

Test your tap water and some distilled water. Distilled water should have 0 ammonia, 0 nitrite, 0 nitrate, and a pH of 7.0.

You can also take a glass full of tank water to a pet shop and get them to test it for you. Take your test kits as well (including the test strips) and test the same sample at the same time. Write the results down in numbers when you do the tests.

What is the nitrite reading of your aquarium?
Nitrate test kits read nitrite as nitrate and give you a false reading if there's nitrite in the water.

How long has the tank been set up for?

How many fish do you have in it?

[danielsaylor]

Over 2 years. I have 2 angel fish 6 Cory's and one pleco. Fish are fine. Plants are fine. Ammonia and nitrites are very low to non existence. Have done several 50 percent water changes every 3 days for a month

[Andy Sager]

Originally Posted by danielsaylor

Over 2 years. I have 2 angel fish 6 Cory's and one pleco. Fish are fine. Plants are fine. Ammonia and nitrites are very low to non existence. Have done several 50 percent water changes every 3 days for a month

What brands are the test kits and strips you are using? Some brands are more reliable than others.

[danielsaylor]

Both are api.

[Joe_D]

Fist of all... do not confuse Nitrate with Nitrite
Nitrite is toxic even at low levels
Fact is plants need some Nitrate to flourish
No one can ever agree what is a too high nitrate level in an aquarium.

So, if all fish are doing great, just continue you regular water changes.

[danielsaylor]

Ok sounds good I haven't seen any change in it so I will just do 50% weekly from now on

[Aiken Drum]

I would trust the liquid test result over the strip test result.

Unless its coming from your source water, high nitrate is the result of high amounts of ammonia. Ammonia is being converted into nitrate.

Typically, a normally stocked tank will produce around 1ppm of ammonia per day. The nitrogen cycle will convert this into nitrate and you would see nitrate rise by about 4ppm per day. A 30 to 50% weekly water change with clean (0 nitrate) would be sufficient to keep nitrate at low levels in these circumstances.

If your tank is producing higher levels of ammonia than this you will see higher levels of nitrates with the same water change routine. Similarly, if your source water has high levels of nitrate in it, the water change wont bring the nitrate down by the same amount and you will see higher levels of nitrate.

Have you tested your tap water as suggested?

Have these high levels of nitrate suddenly appeared?

Your fish would be producing low levels of ammonia in say a 50g tank, but those same fish in 10g would have 5x higher ammonia levels because its being diluted 5x less. What size tank do you have?

[danielsaylor]

Yes my water is fine and I use conditioner in it. I let it set couple those days in between changes. Also I have 32g fluval flex

[Colin_T]

What sort of pleco and how big is it?

How big are the angelfish?

How often and how much do you feed them?

Do you add any plant fertiliser to the aquairum?

Buy a bottle of distilled water and test that. If you get nitrate readings from distilled water, the test kits are dodgy.

[Aiken Drum]

The filtration on a flex tank is basically a sponge block with a small amount of biomedia sat in the middle of it.

Sponges are known as nitrate factorys as they trap detritus, which decomposses, produces ammonia, which in turn produces nitrate. While the sump on a flex can be set up to provide great filtration, the factory set up with the big sponge block is going to produce more nitrate than would be the case for a better set up filtration. For example less sponge and more biomedia would trap less gunk which would then be removed with your water change, and you would see lower nitrate.

Stick with the 50% weekly water changes for a few months and see if nitrate gradually comes down over that time period.

[danielsaylor]

Pleco is small, angels are full size, feed once a day small amount

[danielsaylor]

Ok will keep them up then

[Colin_T]

Sponges are only a nitrate factory if you don't clean the filter. If the filter is cleaned once a month, they don't make any more nitrates than normal.

[Andy Sager]

Originally Posted by danielsaylor

Both are api.

Just an FYI, with the API liquid test, you need to really shake up the nitrate reagents before testing to dilute anything that may have settled out of solution. When I say really shake them, I'm talking about 2-3 minutes non stop of shaking. When you arm feels like it's about to fall off from the shaking, shake for another 15-20 seconds.
Try doing another test after shaking the reagents to see if there is a difference.