New Tank, Approx. 1 month

[TheScientist]

Hi everyone!

I'm new to the world of aquariums, and have a few questions and concerns I'm coming up against:

I have a 20 gallon tank with a whisper EX20 filter, an air pump and the water temperature is around 78-80 F. I use conditioner, and some aquarium salt. I do a 30% water change each week, and seem to lose a fish after each water change.

In addition, I seem to have some fry swimming around (probably bought a pregnant one) - and they seem to be okay (survived a week in this tank).

I used to have 2 Hi-Fin platies, 2 lyretail mollies and 2 red swordtails, but since I started the tank - I've lost the platies, one of the swordtails and one of the mollies.

Does anyone have any suggestions for what I may be doing wrong? The local pet store suggested I use a stress coat conditioner, and I'm looking into planting the tank and air stones.

Thank you for any help!

 

[TMaier]

Did you cycle the tank? And are you using a water conditioner to prepare the water for changes?

 

[TheScientist]

Yes, I cycled the tank before adding the two platies in early January.

And I used the water conditioner before adding the water into the tank (I added the conditioner to the tub of new water).

For reference, the ammonia, nitrates and pH are all fine - I check every week.

 

[BBradbury]

The...

A 20 gallon tank is small and the water chemistry in small tanks will change rather suddenly and puts the fish at risk. Using floating plants like Anacharis, Hornwort and Water sprite will help steady the chemistry. Small water changes don't do much to maintain good, steady water conditions. Small tanks need most of the water removed and replaced more often than weekly. Dissolved waste material from the fish can build up in a small tank in a few days and stress the fish and weaken their immune system. Mollies are especially sensitive to changes in the tank water.

A little aquarium salt is fine, but if you up your water changes to 50 percent every 4 to 5 days you'll improve water conditions and the salt won't be needed. Reduce the amount you feed to a little variety every day or two. The water will stay cleaner longer.

This hobby is totally about keeping the tank water clean and changing a lot of water and doing it often is the key to a healthy fish tank.

B

 

[TMaier]

What about the water temperature? Are you within 5 degrees?

If there are huge differences in the water chemistry that is the only thing I can think of.

Are you moving stuff around? Vacuuming? Are the fish darting around stressed?

 

[TheScientist]

The water heater I have keeps it at 78-80 F consistently, I never see it above 80 and have only seen it get down to 78.

I haven't moved anything since setting up the tank, but I've been vacuuming with the water changes.

I spoke to someone yesterday who suggested even smaller water changes (10%) since it's such a small tank and not a lot of fish - maybe the large changes are shocking them.

 

[BBradbury]

The...

Whomever recommended small water changes, hasn't done their research. Removing 10 percent of the old water, leaves 90 percent of the old, toxic water still in the tank. Consider the water. The fish are living in the water they do all their "business" in. They're living in an unflushed toilet if you see what I mean. By removing the old water more often, before the waste material has time to dissolve, you maintain a pure water environment and the fish stay much healthier and live longer.

B