Can Cardinal Tetra Live With German Blue Ram?
Maybe, with caveats , cardinal tetras and German blue rams share a tight one-degree temperature window, but the pH overlap is narrow and both species have specific water quality demands.
Why
- Temperature overlap is 80-81°F, which works for both species but gives no room for temperature fluctuations.
- pH overlap sits at 5.5-7.0, with German blue rams preferring the higher end and cardinal tetras the lower end.
- German blue rams are micro-cichlids that can be territorial, especially during breeding, and may chase small tetras.
- Cardinal tetras need soft, acidic water in the wild (Amazon tributaries), which aligns with the lower end of ram preferences.
- Both species need pristine water conditions, so bioload must stay very low in a 20-gallon setup.
What could go wrong
German blue rams may claim the entire tank as breeding territory and nip at or stress cardinal tetras during spawning.
Gear for a shared tank
Sized for the 20 gallon minimum this pairing needs. Affiliate links — we earn a small commission if you buy through them.
AquaClear 30 Power Filter
Oversized filtration is what lets you stock two species together without water quality crashing. Rated for a tank slightly larger than the 20 gallon minimum.
Eheim Jager 150W Thermostat Heater
Holds a steady temperature inside the 80-81°F window both species need.
API Freshwater Master Test Kit
Keep ammonia, nitrite, and nitrate in check. Two-species tanks have more bioload and less margin for error than single-species setups.
Better pairings to consider
German blue rams do well with other peaceful tetras like rummy-nose or neon tetras. Cardinal tetras do well with corydoras, rasboras, or other non-territorial community fish.
Related compatibility questions
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