Water Changes

[rwilliams26]

We've received some interesting feedback concerning water changes recently, so thought we'd post this and see what some of y'all might think. We're just running a small, 43 gallon tank (about 50 lbs. of live rock in it), and do 15-20% water changes about once a month...seems to be working just fine for us. We normally mix up 5 gallons of r/o water with measured amounts of "Instant Ocean", and let it circulate with a submerged powerhead overnight. We then will simply siphon out the old and carefully add the new. We've been doing this for about a year. NOW...what we've heard recently is that we should also be checking the ph value of the water and "adjust it" accordingly. Our ph has been running pretty consistent at 8.0 when we check it (usually in the evening...which is when we do water changes). I guess what I'm curious about is whether anyone is actually pre-adjusting ph, and/or doing any other "dosing" of the new water before it goes into the tank. Thanks!

[matt]

You can also aerate the replacement water with an airstone or venturi fitting on the powerhead you're using for circulation. This will really bring up the ph to normal tank levels. IO usually mixes to a pretty low ph.

Matt

[Derek B]

Unless you are doing a major water change, 5 gallons of slightly high or low pH in a 50 gallon tank is not going to cause a problem. Best thing to do is wait 15 minutes or so after mixing before you dump it in ... or do like Matt said and aerate it with a power head.

[Tim Marvin]

I mix the salt with a powerhead for 10-15 minutes and use it. If you mix it for 24 hours you will lose some of the trace elements and calcium because it sticks to the sides of the mixing container. I don't remember were I picked up this information from, but if you mix for 24 hours in a clear container you will see the sides are white crusted in the morning, so all that is lost from the tank.

[Tim Marvin]

Do you leave it for 24 hours? I'm not that patient usually.

[Tim Marvin]

Hmmm don't know. I have always mixed and used. Oh, I do run the water with a powerhead in it all the time. The fresh water that is. Maybe this helps? Then I dump that water into a bucket with the salt, mix it and use it.

[Jimnorris]

I use a 50 gallon glass tank to make and mix my saltwater. I have a Kent RO/DI for the fresh water. I dump a 50 gallon bag of Marine Enviroment into the tank that is almost full. This fills it to the very top. With about 5 mins. (using a mag12 to mix) it is ready for a water change. PH 8.3, Calcium 430, Alk 9.0 and SG 1.025.
Jim

[rwilliams26]

This is great information....Thanks to everyone who's responded! I think we'll cut our aeration/mixing time down to just a few hours at this point, and try to do changes "same day". Tim, I have noticed a little bit of the "crusting" you mentioned after leaving the mixture running overnight. Thanks again! :grin: