Newbie to freshwater tanks

Jae9110

Hi i'm new to fish keeping and getting a 40gallon tank. I have a PH of 7 and water with medium hardness. I was curious if i could mix guppies, mollies, and tetra.

AbbeysDad

Welcome to the forum!
You'll find a bunch of friendly helpful folks here.

The short answer is they are all community fish and do pretty well together. Bear in mind that tetra's are shoaling fish that are most comfortable in larger numbers.
Go to the "Tropical Fish Profiles' (top of the forum page) for details on each fish.

Chr1s

Welcome to the forums.

smit3183

Mollies and guppies need hard water and a ph preferably a little higher than that to thrive. Your water may work but you might want to try other fish.

Byron

Welcome to Troipcal Fish Keeping forum, and to the hobby.

Do you have a number for the GH (general hardness)? And the KH (carbonate hardness, or Alkalinity)? The latter will tell us what the pH may do, as it is normal for it to lower as the water acidifies, unless the KH buffers it. This info will help decide on fish. The water supply people can give you this info, maybe on their website.

As mentioned, the profiles give water parameters and other info for the species. Some are adaptable, some are not.

Byron.

Jae9110

PH is 7.2
Buffering capacity is 120
Total hardness is 50
Nitrite, nitrate and ammonia is 0

Byron

The GH and KH must be ppm (parts per million), to make sense. So that equates to a GH of 3 dGH which is very soft. I would not try mollies, they must have much more calcium and magnesium mineral in the water. Guppy tend to be more adaptable but if it were me I wouldnot subject any livebearer to water as soft as this. The tetra will thrive, as will any other soft water fish.

The KH at 120ppm is roughly 7 dKH so that is going to buffer the pH a bit to prevent it lowering.

If you want some background reading on hardness and pH, have a read:
Water Hardness and pH in the Freshwater Aquarium

Byron.