Can a 2.5 gallon tank be cycled?

[JBosley]

Hello!
I have a nice, simple question... can a 2.5 gallon tank be cycled? I currently have a 3 gallon tank with live plants, that is now fully cycled. And was wondering if it were possible to cycle a 2.5 gallon!

I've heard mixed answers about this! So I'd love some clarification... it will have gravel, some low light live plants, a filter and heater.

[MadameDesu]

I've never cycled before, but many members here say that anything over 2 gallons can be cycled. The bigger the tank, the more stable the cycle.
2.5 can be cycled, but it'll be more unstable because there's less space in the tank for the bacteria to grow. You can cycle it, but you have to be really careful about taking care of the tank. Never rinse the filter media in anything but old tank water and do it gently. Rinse gravel in old tank water. Only add conditioned water directly to the tank instead of filling it with tap and then conditioning. Or at the very least, before removing the old water, scoop out some gravel in a cup and then add it to new, conditioned water in the tank. That way some of the bacteria can be retained even if the rest of the ravel touches chlorinated tap water.
Let us know how it goes :)

[Oldfishlady]

Any size container can be cycled provided that the BB needs are met, however, with smaller tanks with limited surface area the cycle may not be stable-but since you plan live plants-The 2.5gal filter tank should be fine in regards to a stable nitrogen cycle.

Depending on the number, species and growth state of the plants-you will do a silent cycle. Often with the right species, number and growth state the plants will use ammonia for food before conversion and it will take a long time if ever to see the nitrate reading we look for to tell us cycling stage/completeness-but the cycle is still happening and the BB are still colonizing.
Remembering that some chemical products like dechlorinator, plant ferts...etc....can cause false reading as well as the testing products test at a ppm level.

[JBosley]

Thanks guys!

My 3 gallon cycled very quickly with the live plants, and I also used some substrate from my cycled 15 gallon. It was cycled within days... and has stayed steadily cycled for 3 weeks now!

Definitely going to try to cycle a 2.5 gallon tank. I have limited room, and my shelving unit can only hold 66lbs per shelf