Water Changes

[dougie]

Hi All,

In a 400+ litre tank, & doing a water change, would doing a 5% water change daily for 6 days a week (30% total) be as beneficial, or more so, than doing 30% in one go - once a week?

Cheers in advance.

Dougie.

 

[Lunar Jetman]

I'd probably do 30% once a week. That way you're lowering anything like Nitrates, etc in one go rather than small changes which won't have as big an impact.

25% changes would be fine too.

 

[Livewire88]

Depends a lot on your stocking and other things like do you have live plants? and do you dose anything to feed your plants?
 
Without more info it is hard to reccommend a water change regime.

 

[fluttermoth]

Mathematically, larger water changes are more effective than multiple smaller ones.

 

[Lunar Jetman]

Mathematically, larger water changes are more effective than multiple smaller ones.

This.

 

[the_lock_man]

What she said.
 
When you change a second time, you are taking out partly old water and partly new water that was only introduced the day before, and so doesn't really need changing.
 
Look at the maths. If you have 100l, and you take out 30%, you are left with 70l.
 
However, to do that with 3 individual 10% changes, start with 100l - 10% = 90. Take out 10% again, 90-10%=81l. And a third 81-10%=72.9l

 

[dougie]

Depends a lot on your stocking and other things like do you have live plants? and do you dose anything to feed your plants?
 
Without more info it is hard to reccommend a water change regime.

There's nothing in it yet. It's sitting in my garage while I strengthen the floor & do the lighting. I'm also considering building a new stand (2nd hand tank, old stand) .

I'm just planning ahead. Doing 30% per week on my current, 40 gal. Seems like I'll continue to do it that way when the new one is ready.
Thanks for the input guys.