How many water per week should I do?

[shawn barker]

I'm confused about the number of water changes and the quantity of water I should be removing at each change now.

There seems to be so many different opinions on this I am not sure now if I am doing enough.

I generally change about 100 litres out of my 480 litre tank twice a week as a rule using 50 litre of RO and the rest tap water. I only have 2 x 25 litre drums for storing RO so try to work around that.

The tank water seems to be stable at a ph 6.8-7, ammonia 0, nitrite 0, and the nitrate at around 10-20 (I add ferts according to the EI method for my plants).

Should I alter wate changes to daily, every other day and is it OK to mix tap and RO or is it better to just do remineralised RO?

Can anyone clear this up for me, or even confuse me further with a different regimes?

[ILLUSN]

20% twice a week is ok, i prefer 30% as thats how long it takes me to clean the gravel bed. the fish will tell you if its enough or not, if they ever start to look a little down, give them a bigger change, if they're out fighting each other for food from your hand they're fine as it is.

[Merrilyn]

There's a fairly simple way to check the health of your tank Shawn. Test your nitrates.

Discus prefer clean water with nitrates below 10. If you're constantly getting readings of 10 to 20 prior to a water change, then you need to change more water each time, or water change more frequently.

A mix of RO and tap water is fine, as long as your tank remains stable.