Water change/replacement question

[zar]

What are the "best practices" out there for water changes?

- In my 30g tank, how often should I change water, and to what amount? Assume all "normal" chemistry conditions exist -- nothing abnormal. Just doing routine maintenance here.

- When I do a water change (as opposed to just replacing evaporated water), I am altering the SG, true? If so, should water changes be made with pre-mixed saltwater solutions? Or should I continue to just add RO water to the tank like I do to handle normal daily evaporation?

- If I *wanted* to lower my SG, how would I go about doing that?

- When adding pure RO water to the tank to replace evaporated water, should I be concerned at all about the fresh water killing anything (either on the LR or as a tank inhabitant)? For example, can I just willy-nilly toss a gallon of RO water in there without concern? Or should I add it in small increments, avoiding pouring near anything that is living?

thanks!
bruce

 

[axepilot]

>>>>I do routine water changes in my FO tank about every two to three weeks - about 25 percent.


>>>>Your water changes should be made with RO water mixed to the desired SG of the tank. Daily topoffs should be made with fresh RO water.


>>>>You can lower your SG slowly by doing gradual water changes mixed to a lower SG. GRADUAL is the key.

>>>>I add my freshwater topoff to the return side of my sump. I lose about a quart a day.

 

[mogurnda]

- In my 30g tank, how often should I change water, and to what amount? Assume all "normal" chemistry conditions exist -- nothing abnormal. Just doing routine maintenance here.

For a smaller tank, 20-25% every week or two is good.

- When I do a water change (as opposed to just replacing evaporated water), I am altering the SG, true? If so, should water changes be made with pre-mixed saltwater solutions? Or should I continue to just add RO water to the tank like I do to handle normal daily evaporation?

Definitely use pre-mixed SW. Let it mix in a bucket with a powerhead and a heater, overnight preferably.

- If I *wanted* to lower my SG, how would I go about doing that?

I agree with axepilot. Generally what I do is perform water changes with SW of slightly lower specific gravity.

- When adding pure RO water to the tank to replace evaporated water, should I be concerned at all about the fresh water killing anything (either on the LR or as a tank inhabitant)? For example, can I just willy-nilly toss a gallon of RO water in there without concern? Or should I add it in small increments, avoiding pouring near anything that is living?

If you don't have a sump, but have a HOB skimmer or filter, put it into the output section. It's best to put it in a place where it can mix with tank water before getting near the livestock.