We Have A Very Small Aquarium...

[masma]

..we'd been advised to set it up, fill with water and wait two weeks before putting in the fish, this we did. We got 6 Mollies and over 2 weeks 3 died. We took a sample of the water to the 'fish shop' and were told it was very high in nirates and to replace 20% of the water every other day. We didn't think to ask but... should we be replacing it with tap water? (2 more fish have died today, the last one doesn't look to healthy)

[sherrardk]

When himself takes water out of ours (2 x 70ltr) he puts chemicals in the replacement water. We've not had them that long (one since September and one since January). Started off brilliantly, babies all over the shop. Had one or two casualties but they seem fine now but the tanks keep going green. It all seems a bit hit and miss to me.

[Captain2]

Hi masma - presumably you have an aeration pump and have put some oxygenating plants into the tank as well?
We had an aquarium for a couple of years before we moved house and did quite well. We were advised to add a solution to tap water to inprove the condition of it. However I can't for the life of me remember what it's called. Perhaps someone will be able to tell us or I'll look into it tomorrow after work.
Very relaxing hobby - stay with it.

[treetops68]

masma - without any additional info. I would say it looks as though you may have a problem with your tap water. (Get a sample tested as a first step?)

sherrardk - too much daylight getting into the tanks or invest in a Plecostomous (not sure that's spelt right) for each tank.

[mastercraft]

Have you been adding de-chlorinator to the water? Tap water has chlorine in it, which is toxic to fish and the good bacteria that is needed to break down the fish waste.

[mastercraft]

Also, six mollies into a small new tank is overloading the filter. If you have to start again, which it sadly sounds like you will, only add two fish a week. This will give the (good) filter bacteria time to multiply and deal with the nitrates, turning them to nitrites, much less toxic! Good luck!