Water change experts

[FamousGuy]

alright, they say to do a 10% water change weekly....so on a 20 gallon that would be 2 gallons a week assuming the tank doesnt have anything in it besides water....how much water would you actually change if the tank is heavily stocked with rock and sand?  Still 2 gallons?  How much water would actually be in the tank after the displacement?

[Toyfreek]

That's always been a sticking point with me as well.

There are some that say dur to the porus nature of rock and sand that your volume isn't all that displaced others will say tou have a 15 gallon tank. bottom line do up to a 30% change on tank volume. so if you do 2 gallons in a rock worked tank its like 17% or so you would be fine. any thing over 30% will have detremental effects on bioload and is no longer considered benificial, unless it is for the removal of toxins. I am interested in hearing others thoughts on this as well.

HTH,

Toy

[gabe3eb]

I think that you should be just fine, a couple gallons wont be enough to cause any problems... GL,

gaber

[Silvian]

I have a 20gl and I usually change about 1-2 gl a week. Everyone has a thought about water changes, and I think it really depends on the individual tank, if its more heavly stocked you might need to change more water out. Some people just do water changes once a month and have no problems. Just test you water and make adjustments on the water changes.

[Kapelakin]

I do 3 gallon water changes on my 20 gallon weekly.  I figure I have about 15 gallons of water in there, so that amounts to about 20%.  As long as you're not doing anything too drastic, I'd err on the side of larger water changes.