Guppies are dying

Fishtails

Any advice is welcome to this new fish keeper. I have a small aquarium, 6 gallon, with heater, filter. I have had it running for 3 months now. In it I have (had) 1 dalmation mollie and 4 male Guppies. After cycling the tank for 3 weeks, (advice from my LFS) I added the fish, 1 then 2 then 2 more at intervals. The fish seemed happy, then in the last 3 days I lost 3 guppies one after the other with no apparent reason.
I have gravel, a synthetic plant, a live plant and a hidey hole.
The temp of the tank maintains 73F
Any help is much appreciated, as I'm a bit distressed
Thanks in advance

corry

Hi I am also new to tropical fish keeping, but I think you should check your ammonia levels, my daughter has a small tank also (7.5G) and the LFS told us it had cycled after 2 weeks so we added fish to there advice and got huge ammonia readings when I finally bought a water tester myself (and after losing a couple of fish). The tank hadn't cycled... The best advice I would give would be to get yourself a test kit then you know that alls ok :o)

Fishtails

Thanks for the info. I shall sort that out in the morning and go from there. Many Thanks

Inga

I agree that the test kit is a good place to start. Also, I would turn the temperature up a bit. I keep my Guppy tank at 78-79 degrees. They also like a PH of between 6.8 and 7.6 With mid range being favorable. I also do 50-70 percent water changes weekly. How much you change will depend greatly on the amount of fish you have in a tank. If it were me, I would also add a few extra live plants. I hope you do not lose any more fish. Good Luck with them.

Oh and Welcome to the Forum! :)

LasColinasCichlids

6 gallons for 4 guppies and a molly is too overcrowded, and not enough surface area for enough beneficial bacteria to colonize to support that much of a bio load. A molly should always be in a larger tank, 30 gallons or so, its a common misconception that they dont need much space, but they do. Mollies also have a very large bio load.
Sadly, small tanks (under 10g) doesnt leave much for options when it comes to super common easy to find fish. A betta would work, a shrimp tank would work, or a solo Dwarf Puffer. Three guppies total is pushing the limits for a 6 gallon tank (assuming we are talking american gallons that I am familiar with).
An ammonia spike from too many fish is the most likely cause, and not your fault if you are new to the hobby. There are some great articles that can help here on TFK...
A Beginner's Guide to the Freshwater Aquarium Cycle

A Basic Guide to Freshwater Fish Stocking

Bacteria in the Freshwater Aquarium

Water Hardness and pH in the Freshwater Aquarium

It's all about researching what you would like to keep, and making that fish or shoal at home with all their needs. Welcome to TFK.