High Nitrates

[mchisholm12]

Hello friends,

So I have lost a pair of neon blue dwarf gouramis recently in my 55 gallon heavily planted tank. I tested the water and my ph was a little lower than I would like, ammonia was perfect along with nitrites, so my bio filter is working great but I have a massive amount of nitrates. I do regular water changes, every day i use dry ferts and liquid co2 for the plants and run a cascade 700 through it. I have a history of high nitrates with this tank and I am not sure what to do so now I'm really reaching out. I can add pictures if that'd help, see if you can spot anything. Thanks!

 

[threnjen]

How high are we talking?

Have you tested your tap water for nitrates?

What size tank? What's your other stock?

 

[mchisholm12]

I use the API test water kit and immediately as I begin to shake the vile, it becomes bright red. Not yet dark red, but very very red, not mistakenly orange at all. I haven't thought of testing my tap water, I also put my tap water through the brita filter into a plastic tub before putting it in my tank and adding API stress coat.

The tank is a 55 gallon. I have a variety of fish in there.
4 corys
2 red wag platy's (one just gave birth)
2 yellow mollys
5 congo tetras (adult)
5 glass cats
2 pictus catfish (one mature but not super aggressive)
1 large plecostamus
2 silver hatchetfish
2 marble hatchetfish
2 praecox rainbows
3 large red irian rainbows
4 zebra danios
2 opaline gouramis
1 gold gourami
4 red minor serpae tetras
and a couple snails

It's a lot of different fish, in small numbers.

 

[BBradbury]

Hello friends,

So I have lost a pair of neon blue dwarf gouramis recently in my 55 gallon heavily planted tank. I tested the water and my ph was a little lower than I would like, ammonia was perfect along with nitrites, so my bio filter is working great but I have a massive amount of nitrates. I do regular water changes, every day i use dry ferts and liquid co2 for the plants and run a cascade 700 through it. I have a history of high nitrates with this tank and I am not sure what to do so now I'm really reaching out. I can add pictures if that'd help, see if you can spot anything. Thanks!

Hello Mc...

You have quite a few fish in that tank. But, nitrates are at the end of the nitrogen cycle, so aren't quite as harmful to fish. Acurel has a nitrate removing pad that may help. I use Acurel filter media and it works very well. I'm a firm believer in large, weekly water changes. 50 percent of the tank's volume is pretty normal for my planted tanks. Hopefully, your water is good. I float a lot of Brazilian water weed (Anacharis) Hornwort and Pennywort in all my tanks. These plants are great users of all kinds of nitrogen, including nitrates. Might be helpful too.

B

 

[Mebbid]

Wow, I've never seen quite so large of an assortment of different fish.

Some first thoughts:

1. How much do you change with your water changes?
2. How many times daily are you feeding?
3. What dry ferts are you using? Also, how do you dose them? EI, PPS Pro, Or some other method?

I am willing to bet that #3 is where the issues with nitrates are coming from. Potassium Nitrate is commonly added in as a fertilizer in the dry fert packs. While it adds potassium, it also adds nitrates. I had tons of issues with nitrates in my tanks until I switched from an all in one dry fert to an EI fert pack with separate bottles for all my mixes. In my 55g I don't even have to add the nitrate in as my fish produce enough for my plants.

 

[Jmunroe]

A large pleco in a 55 gallon alone will create a huge bio load and with other fish it of course will be worse. Rehome your pleco, do larger( 50%+ at least once a week) water changes and you'll see a difference. In order to get them back under control you should do some large daily water changes. Do you gravel vac? Especially the mess the pleco makes needs to be vac'd at water change time.

 

[Old Scales]

I'm like Mebbid. I don't have to dose the nitrate fert because the fish produce enough. If you're dosing it on top of what your fish are making, it would get high very quickly. Don't let filters getting heavily dirty either. At a point they can become nitrate factories. +1 on rehoming the Pleco also. OS.

 

[Rivercats]

After you test your tap water to see if that is the root of your nitrate issues other reasons for high nitrates can be from extremely dirty substrate (which doesn't matter if the tank is heavily planted with fast growing plants), a dirty filter (nitrates will build up in a filter if proper maintenance isn't done on a regular basis), too high a bio-load, not enough WC's or not enough water removed during WC's, and dosing nitrates via your ferts when your levels are high enough on their own.