Extremely high nitrates - how do fish live?

[hankn]

I just cleaned and checked two aquariums where I work which hadn't had a water change in about a year. The nitrate count was far in excess of 160ppm that the Master Test Kit could see. I can not even describe how deep the red color was - far deeper than the max color. Had to have been 400-500 ppm - at least.

I did a 50% water change and will continue to do so until I get the numbers down - but how did the fish manage to survive - and not just survive but grow tremendously and thrive?

 

[lucy42083]

I can't explain it physiologically, but it's not uncommon. As long as the water quality deteriorated slowly over time, fish adjust to it. It is actually recommended that in a tank with bad OTS like these that you change the water very gradually in small amounts, because the osmotic shock the fish experience when going from very bad water quality to good water quality can actually kill them. I have no idea how fish continue to grow and look 'healthy' in conditions like these, but I've seen it many times myself, like a 12" oscar with good color and no apparent HITH or other problems in a 30G tank with nitrates at like 160ppm. I know that it can't possibly be good for the fish, and must shorten their lifespan, but sometimes they are tougher creatures than we give them credit for. I mean, just think how polluted most of our bodies of water are, and fish still manage to live.

 

[JohnSmith]

... The nitrate count was far in excess of 160ppm that the Master Test Kit could see. I can not even describe how deep the red color was - far deeper than the max color. Had to have been 400-500 ppm - at least.
...

I would have slowed the water changes down a bit, say 10% every couple of days until I had "things the way I wanted them." The shock of going from one extreme to the other can cause disease and kill fish in itself ...

Well, back when I started keeping fish, I don't even know if you could find the test kits which everyone has stuck in their pockets today. I had a guppy tank which had a chunk of elodea in it, guppies were breeding and carrying on to large sizes and ripe old ages--I never changed the water in this tank.

I hear your question and am unable to answer it. Nowadays, it seems, everyone keeps their fish in a constant current of tap water flowing though them!

Indeed, many no longer even have aquariums. They have planted water terrariums with a fish or two in 'em!

Go figure ...

Regards,
JS

 

[hankn]

Oh boy - I hope I don't come to work and they hang me for killing the fish -by improving the water quality! Last time they will let me near their tanks

I'll be there next in 10 days and see how they are all doing. In the smaller of the 2 tanks - I donated about 30 yellow marble molly fry (1 month olds) that I had - so if I kill those - at least it will be my own fish.

 

[toodleypops]

yeah i idi the same thing in my tank (i did an experiment on OTS for 1 year) and i did frequent very small water changes and all my fish are still alive and such. 5,5,5,10,10,10,15,15,20,25. then my water was great. anyway yeah dont shock them. keep it small and they will be fine

 

[Eupterus]

I can't answer your question, however I'm curious why the fish went without a water change for a year?. I'd think even the most low care setup needs water changes more then once a year?.

 

[Squawkbert]

Fish do this in the same way the addicted expose themselves to doses of various drugs that would easily kill a non-user. They slowly build up a tolerance.

As you claen up the tank, vacuum a little section of substrate gently, but thoroughly each change, avoiding setting any toxic pockets loose into the tank water.

 

[hankn]

I can't answer your question, however I'm curious why the fish went without a water change for a year?. I'd think even the most low care setup needs water changes more then once a year?.

The aquarium is in a public greeting area and no one really bothers it other than to feed the fish. What can I say...

 

[hankn]

Fish do this in the same way the addicted expose themselves to doses of various drugs that would easily kill a non-user. They slowly build up a tolerance.

As you claen up the tank, vacuum a little section of substrate gently, but thoroughly each change, avoiding setting any toxic pockets loose into the tank water.

I graval-vaced the substrate and the water in the bucket was pure black. I just hope I see live fish when I go back next week.

 

[Squawkbert]

As long as you didn't stir much of hte crud into the water column, you should be OK.

If you're interested in the "special" issues you're facing, search "Old tank syndrome"