Minimal requirements for a planted tank ?

Some plants will grow best in warmer water, but basically no, you don’t NEED any of that stuff.

If it’s plants only a filter is unnecessary, although some method of circulating water will keep it fresher. Some algae tends to grow more readily in stagnant water.

You also don’t have to change water because the plants will basically filter it as they grow, you just need to replace evaporated water and add fertilizers and/or minerals as needed. Occasionally changing water is still a good idea though as some minerals may build up to higher levels than desirable if you never remove any water.

All you need at a basic level is water, substrate, plants, light, and occasional fertilizer. CO2 can vastly improve plants ability to grow though, so you may want to purchase a CO2 system or build a yeast reactor.

/r/PlantedTank Thread