pH too high

[kjjoseph74]

Thank you for your help in advance.

I have a 75g with 45lbs LR and 20 gallon refugium with 24 hr lighting. The pH of the tap water that I use is 8.4. When I drip in Kalk, my calcium goes to 350 and my dKH goes to 10, both of which are fine with me...however, my pH then goes to 8.6 which is a little high. I am not sure how to get it down. I have tried to use vinegar with the Kalk, but that does not do it. I want to get parameters perfect before getting coral. Any suggestions?

Other info: amm, nitrite and nitrate = 0
440W metal VHO
1 flame angel
1 very small purple tang
1 cleaner
1 coral banded
6 scarlet hermit

thanks alot
kevin

 

[randy holmes-farley]

How did you use the vinegar? Some ways give greater pH reductions than others. Adding it after the limewater is settled and poured off of the solids works best. Adding it while there are still lime solids around will deliver more calcium and alkalinity to the tank, but won't lower the pH as much.

There aren't many other good options, but better aeration is one.

Here's an article that describes how to solve pH problems like this one:

http://www.advancedaquarist.com/issues/ ... 2/chem.htm

 

[kjjoseph74]

I first added the kalk to the vinegar, then added the water. I will try the other way and hopefully it will work some, but I am doubtfull that it will keep the pH 8.4. Any other options? My aeration of the tank is excellent, as I have a refugium with 700gal/min flowing through the turbulent tubes.

thanks
kevin

 

[randy holmes-farley]

I'm sure that if you add enough vinegar, the pH will go as low as you might want. Whether you want to add that much is another question. How much did you use?

FWIW, it's not the order of addition that matters, but the relative amounts that end up in the solution that is dosed.

A temporary measure is to add some soda water to the tank, but that gets expensive. THis is just a way of speeding up CO2 entry to the tank.

Aeration too, as I said, is a way to reduce the pH. Don't fool yourself. If aeration were perfect, you wouldn't (couldn't) have a pH problem. You have a problem because the tank is deficient in CO2. Full equilibration of CO2 is actually quite difficult, unlike equilibration with O2.

Remember, air has a ton of O2 in it, and not much CO2. Likewise, tank water has way more CO2 in it than O2. Limewater puts a huge artificial need for CO2 on the tank that is almost never fully met in any real reef tank (hence the higher pH than is present in tanks using CaCO3/CO2 reactors, for example).

 

[kjjoseph74]

thanks for he replies, I appreciate it.
by the way, Randy, I grew up next door to you in Lexington

take care
kevin

 

[randy holmes-farley]

Not around here any more? I'm giving a talk to the Boston Reefers Society in February.

 

[Gatortailale1]

Did I miss it, what brand of test kit are you using?

Salifert is one of the best if you can't afford PH Monitor.

Craig

 

[kjjoseph74]

Most of my test kits are Tropic Marin. I did not expect there to be much of a difference between test kits until after I bought them. Then I started reading various opinions (and strong ones, at that) about different test kits.

kevin

Randy--I will actually be back in Boston next week...can not wait.

 

[aquarist=broke]

Try to keep the pH low 'cause I think high pH equals "Brick" like substrate.