water changes with zero nitrates?

[KLN]

It has been my understanding that water changes were done largely to keep nitrates controlled in a fish-only tank. Now that I have learned a little more and established the right conditions to keep nitrates at or near zero naturally, how important are water changes? I can't see that I am accomplishing anything with them, except to upset everyone in the tank.

[ReefRaff]

you still need to replace usefull trace elements. this is best done thru water changes.

[cmor1701d]

this is best done thru water changes.

Yep. I've read/heard that some don't do water changes and add trace elements through additives. I still belive that water changes are essential to maintain water quality, just my opinion.

[jamal-188]

I think water changes are less necessary in a FO tank, or should I say they aren't required as often, they are still usefull/necessary in any tank to remove DOC's as well as replace trace elements.

[Biggen]

I agree with what everyone above has said. Even if nitrates are low, water changes will replenish the all kinds of trace vitamins and minerals that the fish and inverts need. Water changes will also replenish the ALK of the water so that the pH doesn't begin to fall.

FYI, I have one friend who has two SW tanks in his apartment. He hasn't changed the water in either of those tank in about a year. He simply keeps adding FW to maintain the correct salinity value. I would love to test both the pH and nitrate in those tank. Nitrate would be off the scale and I bet the pH would be in the high 7.0's. I am surprised anything is still alive in the tank.