Water Changes


New member
Hello All,

Im relatively new to this hobby and have a 40 gallon tank that probably has much less than 40 gallons in it considering all the live rock I have in it (44lbs).

I try my best to do routine water changes, one every 9 or 10 days...but now that I have built my rock up high, and have some Xenia up near the top, even removing 10 gallons will leave them dry.

A) How long can I leave them like that?
B) Should I even leave them like that?
C) Do most people pump the water in?

Trying to figure out a safe and efficient way of doing this.

Any and all help is greatly appreciated.


New member
Leaving xenia exposed will stress them out, but it will not kill them. I have xenia in my overflow and they are out of the water for probably 10 minutes once a week. They retract for about an hour but come back and pulse just like before. Try to have your replacement water pre mixed to reduce the time. I really wouldn't be that concerned. If it happened every day that would be a different story. Hope this helps.


New member
When I do water changes on my 55 I do 7 gallons. It takes me about an hour to do the change....I would think as long as things do not start to dry up. I would leave them like that again as long as they do not dry up....I just take the water out of the main tank and then poor the new water into the sump to let the pump do the work


Premium Member
When I do water changes, sometimes my rocks and corals are exposed for a little while. Splash them with water every 2 minutes or so to keep them wet. Don't let them dry out.


New member
Im trying to figure out a way I can pump the new water in, while pumping the old water out. Need to pull out a sheet of paper and a pencil. Thanks for all the help everyone. Very kind.


New member
The xenia will be fine as many corals do perfectly well being exposed for hours at low tide. That being said...I don't recomend hours but a short period of time with during a water change is fine. I would turn your lights off however.

I would remove and add water via the sump. If you don't have a sump the tank is fine. In either case, an inexpensive power head connected to some flexible hose will work great. You can even use the ph with a shorter piece of hose to force water in nooks and crannies to blast out detritus.

Needless to say, plug the ph into a GFCI outlet!

Good luck!