dying fish

[midcuk]

any advice is most welcome, i have a juwel vision 260 which is well established heavily planted with sand substrate, it has been running successfully for approx 3 years but over the last 6 weeks i have had fish dying for no aparent reason, it has happened to most of my fish (the rare or expensive ones naturally) and there is no aparent reason for it any ideas

the water quality ph nitrate/ite etc are all fine and have remained unchanged for years, i still feed the same foods, perform the same water changes etc as i have always done and yet this keeps happening. i have not added any new fish lately or used any different remedies and it is driving me mad trying to find out what is causing this problem.

the only signs ive had that a fish has been poorly is a large rainbow fish seemed to go very pale and loose its colour the dy before it died, it was still as active as ever and fed readily but the next day it was dead.

anyone got any idead coz im totally bewildered.

ps i took a sample of my water to my local aquarist to check incase my testing equipment was faulty and he agreed with me that everything was fine infact he said levels were "perfect"

chris

 

[OrionGirl]

Any new ornaments? Any changes to the outside--painting, floor cleaning, etc? Have you checked the temp? Heater malfunction can be a killer.

What all was in there? Could be that the fish are reacting to crowded conditions, or something similar.

 

[midcuk]

as i said nothing has changed for years everything is the same heater ok, never use polish on or near tank no decorating (which is a good point u mentioned never thought of that one) but nope nothing like that.

then tank was also quite sparcely populated because i iwas contemplating changing to marnie so hadnt bought a fish for over a year now. (had approx 12 fish in it ranging from a couple of small barbs to a medium size silver shark).

it really does have me baffled all i can think of is the lighting is the only thing that needs replacing as the tubes are reccomended 2 b replaced every 6 month and its been in 8 but that cant effect the fish ! there are also a lot of snails these days since the clown loach died perhaps that has something to do with it ?>

 

[OrionGirl]

Well, the death of the clown loach probably was the first problem, I'm guessing? Clowns are very long lived, 15+ years is normal. How big is the tank? Snails won't really harm a tank. They might not be attractive, but they aren't toxic, and are usually decent detrivores.

The light tubes may cause an algae bloom, but you'd notice that, and it would be really bad before it killed off any fish--we're talking pea soup thickness first. The main problem with algae blooms is oxygen depletion, so bottom feeders are affected first, usually...But do you notice a serious green color to the water? If not, I'd question that theory closely.

 

[midcuk]

nope no algae bloom what so ever apart from a slight case of hair algae on one of the plants, the loach was from my previous tank and i had had it for 6 years and got it of a mate who had it from small fry for a long time before that.

totally a mystery im really stumped as to what it is.

not sure if i need to clear it all out and start again form scratch a bit drastic but cant really think of anything else

 

[Faramir]

How deep is your sand? And is the tank planted?