Dying guppies with few symptoms ?

[ascension101vr2]

Ok I have a 30-35 ( when I did a calculation on it it said it was at 32 gallons) gallon planted tank that I keep my guppies in. The water specs are as follows
NH4 0
Nitrite 0
nitrate between 5 and 10 ppm
pH 7.4

10 guppies
7 leopard cories

No new fish have been added for a month. I have a filter that hangs on the back of the tank with adustable flow and the water is aerated. The temperature stays between 76-78 depending on time of day, I add a very little bit of salt every other water change. Change 10% to 25% of water once a week, vacume gravel half one week half the next. I feed once a day with flake food and once every other day with algae disks for the cories

Symptions include lethargic, listless, will eat if fed, still has good bright color, no swelling, no fungus visable, no bacteria slime visable, normal slime layer on the fish.

let me know if anyone has any suggestions

[Roland]

There may be little you can do for your guppies. A large percentage of the guppies you see for sale at your lfs are so inbred and therefore of such poor quality that they are basicly doomed - dead fish swimming. They are certainly not the hardy fish fish they once were. Its a shame, but its a fish I steer well clear of now.



:(

[swany]

This is parasitic. Treat with 1 teaspoon of salt per gallon of water and an anti-ich remedy such as "quick-cure." May also require anti-parasitic food.

Guppies tolerance for ammonia is very poor, especially when the tank's biological filtration is not up to speed.

Sometimes guppies can be sensitve to the pH fluctuations in a planted tank. You may notice their condition deteriorating more toward the time the lights go out.

Good luck.