Tank cycling Question?

[jonruthy]

Hi,
We have a 200L Feshwater tank it is cycled our water is as follows:
PH - 7.6
Ammonia - 0
Nitrite - 0.5
Nitrate - 20

We Just finished treating for white spot and last week have done a 25% water change, plus cleaned the gravel, our Question is should we do a water change every week or once every 2 weeks?
Many thanks
Jo n Ruthy
:confused:

[MandyL]

How long has it been cycled? The nitrItes should be 0 in an established tank. Personally I do a 10% water change weekly, but opinions vary (and mine is kept really clean by the plants). 20% weekly might be a better bet for you.

[jonruthy]

Hi,
Its been cycling for 6 or 7 weeks now, iv just this min done the test i put up.
So i just wanted to make sure about the water changes, i don't want to be starting off a mini cycle, as i hae read about that on here already.

[Wild Turkey]

Hi,
Its been cycling for 6 or 7 weeks now, iv just this min done the test i put up.
So i just wanted to make sure about the water changes, i don't want to be starting off a mini cycle, as i hae read about that on here already.

Yes unfortunately your cycle has taken a while, and is still being established. As mandy said your Nitrite will be zero in a cycled tank. DO NOT mess with gravel cuz yes it will slow the establishment of the cycle. Generally, once your tank has been cycling for a while (established) you have to disturb the gravel quite a bit to cause a mini-cycle. i do more like 40% weekly but as mandy also said, everyone does it a little different. I would avoid doing any major water changes until you have established the cycle, even if you have fish, 0.5ppm NI is not very harmful for fish, so skip the wc for a bit.

[RainMan]

Water changes do not mess with your cycle... like others mentioned (do not touch filter or gravel). And as turkey mentioned... nothing to panic about with your nitrite. But, do keep an eye on it. Your cycle will take a while to stabalize.

You can test your water weekly to get an idea of where you nitrates are... if they get to high, then change the water. 10-25% weekly is good for your fish... 25% every other week should be mandatory. Some people do 50-75% once a month. But, stay away from that thinking. I used to do that, back in the day. My fish are much happier with more frequent waterchanges. Again, if your nitrates get to high (or ammonia, nitrites) then increase water change frequency and/or volume.