What pH is everyone aiming for?

[mikeatjac]

Psionicdragon

First check your PH probe.

Second do a bubble test.

I think cediss did not read your question correctly. I know of no CR reactor that's output is more than 7.8 and still works. My korallin CR manual says to set the PH effiuent to 6.5 - 6.8. See page three.

You could change your CR media. For example, ARM recommends a PH of 7.5 coming out of the CR. Is the Alk output steady? and at what level?

When you added Kalk, how did you do it? Drip or slurry?

Finally, you could turn off your CR and just drip and see what happens.

 

[Meisen]

Right on aurora,
Calcium reactors, while they temporarily depress pH with CO2 saturated effluent, actually have a net function to stabilize it upwards. The way they do that is by liberating both calcium and carbonate from solid CaCO3. The carbonate is a major component of the buffer system in saltwater and when balanced properly, it actually prevents low pH swings when the tank isn't photosynthesizing.

This assumes of course that the Ca reactor is adjusted properly and that ventilation on the tank is high. When run on a pH controller, they can be a powerful stabilizing agent in a reef tank. The reactor will likely run predominately at night in the begining unless your pH is high to begin with. As the dKH comes up over time, the unit will likely run for shorter durations more frequently.

 

[mikeatjac]

cediss

I will be back in this weekend to give you some ref.s on the benefits of a higher PH.

I am talking about a stable PH enviroment.

I only have one book with me. Anthony Calfo's Book of Coral Propagation.

See page 179 para one. "Average seawater has a PH of 8.4 and every attempt should be made to maintain seawater within tenths of a point of this target".

 

[Meisen]

Back to the original question, sorry. I keep my system at 8.2 as much as I can. Sometimes in the winter with lower ventilation happening, it will go as low as 7.9 but I feel that not ideal.

The concern for me isnt only that the pH is low (Some corals may stop calcifying actively at pH levels as high as 7.6) but that it represents the buffer system being deficent. For SPS, keeping the building blocks of calcification in stable supply seems to be pretty key. Watching and reacting to a pH monitor shifting is a lot easier than testing for dKH three-four times a day I guess.

 

[250G]

I tend to agree with aurora on this. For years I never even had a ph meter. I recently bought one (as well as an ORP meter), just for interest sake. My thought was that these may assist in detecting a significant problem, and just to understand the fluctuation.

I learned my tank hits 8.1/8.2 during the day and 7.9/8.0 at night. I run my co2 reactor kinda fast and dose (drip) kalk 24/7.

 

[cayars]

<a href=showthread.php?s=&postid=8724277#post8724277 target=_blank>Originally posted</a> by cediss
Cayars and Aurora,
You both are posting truth here to one degree or another. I agree that cayars may not completely grasp the chemistry. As Aurora has pointed out there is basic chemistry at the heart of this issue. An equalibrium of acid and base is what keeps the pH stable. As CO2 dissolves into the tank water it immediately forms carbonic acid. The carbonic acid then dissociates into carbonate and bicarbonate. All this occurs in a shifting equilibrium reaction. If the equation is driven to far to the left or right the pH will not want to remain stable at around 8.2. And will either become more acidic or basic depending on which way the equation is being driven.

Cayars gets the chemisty. Did I not pretty much say exactly what you pointed above in one or more of the posts above and even mention the different elements and what not that "make up" the PH buffer and explain at a high level overview how this is effected and how you can adjust it long term by your choice of alkalinity boosters? What do you think I don't get?

 

[JER-Z]

<a href=showthread.php?s=&postid=8709111#post8709111 target=_blank>Originally posted</a> by RichConley
I've never checked mine.

same here...

i don't use Ca reactor or kalk. just a slow drip of 2-part via medical dosing pump...

honestly the only thing i ever test anymore is alk and Mg on a weekly basis prior to water changes.