More sensitive than neons and needs soft, slightly acidic water. When conditions are right, the color is overwhelming.
The largest group where none died in 90 days. Tap water mixed with RO water (share shown per tank) · black sand · bacteria starter on day 1 · fish added on day 10 · 25% weekly water changes.
It likes soft, acidic water. Plain tap water (around pH 7.7) was too much, so this was calculated with RO water mixed in. Bigger tanks hold more water and their pH drops less, so they needed more RO water. But mixing in 90% RO water used up the buffer (KH), pH crashed and all of them died.
Run a 60 cm standard tank with 9 yourself →The same rules the engine uses for tankmates.
No eating or bullying either way, with plenty of overlap in temperature and pH. Fish that swim at a different level come first.
The numbers on this page come from the Water Kiwoogi simulator model; real tanks can differ.