Water changes for a cycled tank

[LizzyP]

I have a 3 gallon fully cycled tank. Only took 4 months ;)

How often should I be doing water changes now? I've been doing 50% twice per week but it's getting a bit hectic over here with school starting back up.

Thanks :D
Lizzy

[vilmarisv]

You need to test for ammonia and perform a water chage when you get ammonia reading.
For a 3 galon cycled I would say 1 25-50% change per week will do but you really need to monitor that ammonia.

[aokashi]

if it's cycled... you do whatever WC neccessary to reduce ur nitrates to be sustained at a safe level...
ie...
ur nitrate should be max 20ppm at every weekly WC

[Hallyx]

Besides nitrates, a weekly water change also removes DOCs which are not removed by the filter. (DissolvedOrganic Compunds like pheromones and other things I'm not really clear on)

I do a 50% weekly change in my 2.5g and 3g tanks. Some keepers do more. With just a few slow-growth plants, my nitrates never exceed 10ppm.

[Dutch]

Smaller volumes of water tend to have less stable water chemistry so you should rely on testing for a tank of about 3 gallons.

[Bettanewbie60]

Here...OFL just posted this..it's great!
http://www.bettafish.com/showthread.php?t=115758
All about water change schedules!