[mogrann]

Hubby's new fish died today. He has had the tank about two weeks. Put water in it let it sit for 24 hours. Then got the fish added them after soaking the bags in water for a period. It has been about two weeks since the fish have been swimming in the tank. They all died within a few hours of each other. One is left but swimming on the bottom, we fear he won't make it either.

Any ideas on what we can do differently for next time. They were types of goldfish and an algae eater.

[odinn7]

Have the water tested for acid and ph levels.
Where I live, I use well water and the ph levels are very high. I put fish in the tank when I moved here and they made it about 2 weeks like yours. I took everything out, cleaned it, and started again....same thing. I then realized it was the water and tested it. My only solution at that point was to buy water from walmart in the gallon jugs (walmart spring water) and fill the tank with that. No problems from there on. I keep a gallon sitting here to add when the level gets low.

Not saying this is definitely the problem but it sounds like it is. Most pet shops can test the water for you or you can buy a kit which is pretty cheap.

[mogrann]

Thank you Odinn. I will let hubby know. He worked so hard on making the tank look nice with fake plants, bought a new filter etc. The tank looks good I will let him know no more fish until we test the water.

[Curlyben]

You didn't allow the water to cycle. This is a natural process that balances the levels and allows the growth of beneficial bacteria.
Here's a few pointers: How to Cycle a Fish Tank

[DrGuy]

Yup, Got to cycle the tank. If you still have fish alive in the tank then you'll be doing a fish-in cycle. Generally you cycle the tank before adding fish, but, kind of late for all that. The key to fish-in cycling is keeping the ammonia level low enough through water changes that the fish can survive while the beneficial bacteria grow.