Water changes and Top off - How often?

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dmolavi

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I'm used to doing weekly WC in my freshwater tanks, but being new to SW, I'm not familiar w/ the "best practices" there...I will be spinning up a 20G FOWLR shortly once my rock is cured.

- How often should I change water? I do weekly PWC on all my FW tanks.
- How often should I top off, and how do I know when to top off? Should I monitor the specific gravity daily, for a few weeks to see what the evaporation rate looks like, and adjust top off accordingly? I don't want to put in an ATO at this time...
 
I have a sump on mine so I have drawn a line on it when the water drops below that line I top it up which is usually every other day. also I do water changes every other week and that seems fine but if you are doing weekly water changes at the moment I would say that would be good as that is what majority would probably recommend anyway
 
I don't plan on running a sump with this tank, given that it's only 20G (and might become a sump for a bigger tank later :) )...I'll just add it to the rotating weekly schedule of PWCs :)
 
Sorry yeah you could still mark the tank though to show the water levels dropping, you could also have a look into an auto top off device if it is something that your worried about
 
Is it okay to top off the main display tank with just ro do water? Im currently going thru about just under a gallon a day... Reason im wondering is due to all these new things im hearing on how topping off with ro di will lower calc mag and dkh over time. I want to know why. Why now? Has everyone always buffered their ro di ? I doubt it...
 
When you see the water is low maybe filter splash or you see glass add rodi. Don't let it get to low then there's a swing in salinity . I top off two 32oz cups a day just pour it in tank or sump.buy a 5 gal bucket of to and your good. Never had a problem with adding ro but I like doing weekly wc.
 
I think the way to do it is to top off with RO/DI water, since when the water evaporates, it's only taking water with it, none of the salt or other buffering minerals.
 
True true, i do weekly water changes as well, but i ment the properties of ro di. Neutral and lesser pH value being added directly to our tanks. I heard that with not matching temp and ph of top off water will cause ph and dkh to drop over time.. Not sure why. But i would love to agree with both you. All i ever do i top up about a gallon, over two periods of the day. Ro di is all i use
 
Yes, the temp has to match, and I would assume that whatever shift in pH was caused by the evaporation and increased concentration of the minerals in the tank would be returned to normal when the RODI water was added.
 
I don't think to much about that I just try to keep my hand out of the tank for one day! Like was said I think the minerals stay in and new added with wc.
 
Awesome, i currently have the temps as closr as possible im using room temp ro di which wits between 70-73 deg f. My tank is higher around 79 80. Only reason is because i cant put a heater in a gallon jug. And 5 gallon jugs are big bulky and also a pita to get just however much heated water you need. All pending no auto top off. Like me . Ive never had an isse
 
topping off doesn't lower your calc/mag/alk levels...corals using them up does, and when you just add ro/di you're not putting any more in. So, what you've heard/read is partially right. Many people add things to ro/di to make up for it, kalk being one of them. There are many products that "balance" ro/di, but i'm not a fan of those considering that by nature ro/di should be "balanced." if its not, then maybe a filter change is in order.
 
I agree with uh oh. Don't add anything to ro. Every tank is different what works well for me might not work for someone else. I add cal,alk and seachems fuel. If I take everones advice I'll be broke. Good lfs won't sell you what you don't need. Little off subject!!!!
 
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