Mollies dying left and right! Please help

[Burkey]

I'm in real trouble here. I've been keeping fish since last January with very little illness (ick and cotton tail only) Now I've lost three gold dust mollies and the forth is currently experiencing the very sad "spin of death." They appear to become disoriented (can't tell bottom from top) and pop eyed and eventually spin themselves to death. I have been treating with Quick Cure @ half strength for two days and for the past two days have used full strength. In between I did try Melafix.

My stats: 20 gallon tank, 7 gold dust 2mos. old babies, 14 newborns, 1 black lyra tail mature, and one very small mature black lyra tail. Nitrite is 0, Ammonia 0 Nitrate is high, pH is 7.2.

I'm truly desperate, any help you can lend would be very much appreciated.

 

[LittlePuff]

How much salt is in the water?

Kim

 

[Menagerie]

Nitrate is high

How high?

If they are suffering from popeye, this is most likely a bacterial problem.

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Corneybacteriosis
Symptoms: Bulging eyes
Treatment: There are a few commercially available products which treat corneybacteriosis. Penicillin and tetracycline are among them.
Information: Corneybacteria causes swelling in the head which will push the eyes outward. It is caused by overcrowding and water of poor quality, having an excess of ammonia and / or nitrites.

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POPEYE
This is a symptom, not a disease. It is usually caused by swelling behind the eye (or in the eye). The swelling may be caused by many factors but is most commonly caused by bacteria.

Also check out:
http://www.aquatronicsonline.com/hobbyist/hobbyist3.htm

Search those three sites and see if anything else matching what your fish are suffering from.

Mollies can benefit from salt in the water. Get some aquarium salt and start with a teaspoon of salt per gallon. This may also help get rid of what ever is affecting the fish. Before adding the salt, do a 25% water change.
What temp is the tank at?
How often do you do water changes while vacuuming the gravel?