About FishPicker

FishPicker is a free tool for planning a freshwater aquarium. You choose a tank and some fish, and it tells you whether they can live together before you spend any money.

How the checks work

• Temperature and pH. Each species has a range. Fish can share a tank only if every range overlaps.
• Tank size. Each species has a minimum tank, based on its adult size and how much it swims.
• Group size. Schooling fish are flagged when there are too few of them.
• Behaviour. Each species is tagged with what it does: nips fins, guards territory, hunts smaller fish, eats shrimp or snails. Two species are flagged when one's habits put the other at risk. A list of known problem pairings covers the cases a general rule misses.
• Stocking. Each species is weighted by how much waste an adult produces. The total is compared with the tank's volume in gallons. It is an estimate, not a measurement.

What it cannot tell you

Individual fish differ. Some bettas tolerate tank mates and some attack everything. Care ranges also vary between sources and between wild and tank-bred fish. Treat a "yes" as a good starting point, watch new fish closely, and check with your seller.

The checks cover the 100 animals and 14 plants listed on this site. A pairing that is not flagged has passed these checks. That is not a guarantee.

Images

The fish and plant images are AI-generated illustrations. They show typical colouring and shape, and they are not photographs of real animals.