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Corrosion of commercial fish tanks after CuSO4 treatment

We culture guppies in aluminum raceways (540 gal) for mosquito control. We had a chronic bacterial problem and followed California Department of Fish and Games recommendation to treat this fish with copper sulphate. There were two 3 day treatments in three of our 10 tanks. Since those treatments we are seeing pitting and oxidation in the bottoms and sides of those tanks. We have drained and cleaned those tanks several times and the oxidation continues. Is there anything we can treat those tanks with to stop this process? Can we paint/epoxy, over them after we stop the oxidation? We have a few small holes already going through these tanks. Your help would be greatly appreciated.

Sincerely, Woody Schon

Werner P. Schon
fisheries biologist - Elk Grove, California, USA
2003

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2003

Werner,

I can't help you re what chemicals you should use for your guppy tank but can't help wondering why you'd use a copper compound because I was told aeons ago that any schools nurturing fish eggs which have copper piping leading to them, equals dead fish ... and now they opt for plastics!

Re epoxy ... the advantages are that it will cure under water. The disadvantages are cost and very sudden curing time versus polyesters and vinylesters.

May I suggest that if you opt for epoxy, then use a very thin (prewetted, of course) fibreglass matt to prevent cracking of the resin.... ie. apply the wet epoxy and immediately then the matt.... any good supply house will give you better information !

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).