add stuff to R/O top off

[George771177]

i want to add a buffer to my R/O water. I hate to add just R/O water because the ph is like 0. I finale got all of my water parameters right and dont want to screw them up, but i need to add some top-off water.
Current parameter:
Nitrate- 0
Ammonia- 0
PH- 8.2
Calcium- 400
DKH- 10

I dont want to screw up my ph. I could add some kalkawasser water to it?
Reef safe buffer brings up to 8.3 and will not take above?
???????????

[funkpolice]

I'm in the same boat. My ph has been slowly dropping for the last 4 months, and I think increased surface area, leading to more topoffs is part of the problem. I've heard kalk is a good solution.
bill

[George771177]

i know what you mean i has to be the top off's i never had a real problem until i increased my water changes. I am just a little skeptical about the kalk because it can bring the ph to a dangerous level thats why iam thinking for just top offs the 8.3 buffer is the way to go. I know some people on here hate to hear about buffers like the one iam describing, but just for top-offs iam assuming it wont affect the tank that much just the R/O i will add it to.

[rmlevasseur]

I top off with kalk and it works great, but I do love having a calcium reactor. If the PH gets too high the CO2 kicks in and takes it down.

Funk, since you live in Il and say it has been dropping for 4 months, my guess is that your lower PH is due to your house being closed up more because of the cold weather. Adding an airstone to a sump with a pump that draws in outside air can make a huge difference. I tapped into my air exchanger, and blow fresh air into my collection cup where the venturi can suck it in.

[funkpolice]

does outside air make that big of a difference? I read that before, but I didn't think it would really matter. I have a very basic understanding of the relationship between ph, co2, and alkalinity. I didn't think there was a big enough change in the co2 concentration to make a difference. I'll try running an air line out the sliding door and see what happens. Thanks for the tip.
bill

[rmlevasseur]

Try to get your skimmer to suck it in if possible. Give it at least 48 hours.

[funkpolice]

I have an aqua c remora pro, so it would be hard to get it to the skimmer. I'll buy a cheap air stone tomorrow.
bill

[joephys]

Topping off isn't going to be the direct cause your PH to go down. I wouldn't add any buffer to the RO water, its just going to cause a temporary fix and eventaully get used up and cause the pH to drop again. Kalk is ok since its a calcium supplement, but it isn't a buffer.

The reason RO water seems to have a lower pH is because it lacks buffering capacity, so CO2 in the air dissolves and immediately lowers pH. Once added to the tank, the effect should be negligible.

If it seems like your pH is lowered when you top off, its probably because you decrease the concentration of carbonate. I think it is better to look at it as evaporation is increasing the concentration of carbonate. I would test your carbonate hardness and make sure its around 10 dkH.