Jay

Just a hunch here... I"m with Loman here IMO it has something to do with water changes

Nitrates being that high also indicate that other non measurable dissolved organic compounds and chemicals are present in the water column at a high level. When you reduce those compounds drastically and quickly, it is possible for fish to suffer osmotic shock and die.

I do not see any discussion on deep vacuuming the substrate in order to cut down on heterotrophic or anaerobic bacterial activity which could be a major contributor to the problem.

I would be cautious about reducing the Nitrates too quickly.

Regards,
Jay

googs13

Jay,

I use the Python...so I do vacuum deep into the substrate. I hope that's not the problem. I have been using the Python for a long time though.

orb4me

Are your fish dead or missing? Do you have an Underground Filter going? A dead fish in the filter?




tx Jay, I didnt know about lowering Nitrates to fast.

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If all is not lost, where is it?

Jay

googs...

There are only a few sources for excessive nitrates.

The nitrogen cycle.
Tap Water
Over Feeding, over population.
UGF filters
Filters that are not cleaned on a regular basis.
The activity of heterotrophic bacteria on organic compounds (fish food and fish waste) compounded by not vacuuming or an insufficient water change routine.
Dosing NO3 for plants etc.

You need to take a step back and find what you are overlooking.

Regards,
Jay

oOOOo

Perhaps test the nitrAte level in untreated tap water, before adding to the tank? That would eliminate one easily isolated and tested potential source anyway.

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2.5g Nursery: 30?-9-7-8-8-1=0 medium Guppy fry
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