nitrate levels

[Carlos & Siran]

The nitrate levels in our sunsun tank is elevated and we're not entirely sure why. There's no plants ATM (we've purchased a Aquaone 850, and will heavily plant it and swap the fish over then)

We do weekly 50% water changes, the tank has lots of rocks which make it difficult to gravel clean. But yesterday we noticed one of the YoYos lying on his side so we did a full run of tests and found the Ammonia was at .25 the PH was 7.6 and the nitrates were 5.0 and the nitrites were 0.

So we pulled all the rocks out and did a thorough gravel clean, a 80% water change and added stress zyme. Last night the ammonia and nitrites were all 0, Ph was 7 but the Nitrates were still 5.0 and it hasn't changed this morning.

The fish all seem happy, and the water looks beautifully clear.

The tank is 160ltrs, stocking rates are 2 angels, 2 yoyos, 2 kribs, a GAE, and a rainbow shark, all fish are adolescents. The filters is a Eheim 2215 and the built in filter does 900ltrs/hr.

Does anyone have any ideas? are we missing something?

Cheers all.

[Jennifer]

Some water sources have high nitrates. Plants will help 'soak' it up. Shouldn't be too harmful to the fish at low levels though.

[kiwiplymouth]

I looks like you have had a mini cycle for some reason which has now probably finished.

Have you changed your brand of fish food or your feeding regime ?

I wouldn't be worried about a nitrate level of 5.0, my tanks sit between 10 and 20

[Morcs]

Generally nitrates are harmless. below 40ppm is perfectly ok for most fish, above that will probably cause stunting.

Some fish like discus can get stunted at much lower nitrate levels i believe.

[snookie]

I looks like you have had a mini cycle for some reason which has now probably finished.

Have you changed your brand of fish food or your feeding regime ?

I wouldn't be worried about a nitrate level of 5.0, my tanks sit between 10 and 20

what he says

[Floater]

I read somewhere anything above 25ppm of nitrates is no good for discus.

[JazzyJeff]

Have you added any fertilisers?

[Carlos & Siran]

Nope, no plants. We checked the nitrates out of the tap and they're 0.

Think the mini spike happened because we never gravel cleaned under the rocks, was real grubby.

Not entirely sure why Nitrates are still elevated but as people have said those levels aren't dangerous, we'll just keep and eye on them.

The bonus of gravel cleaning seems to be that for the first time ever we have a water melon, and our tomatoes are fantastic. :bounce:

[alanmin4304]

Where abouts does your water supply come from? 0 is unusual.

[Carlos & Siran]

Natural spring on the property, has an abundance of crayfish, would that make a difference?

[alanmin4304]

That is possible I guess. Usually there will be some nitrate in rivers and streams from fertilizers etc.