riddle me this on ph

[kirkland]

we've had our reef tank for 14 months now. we get ro/di water from lfs in the area for water changes and top offs. when i do water changes, i add the salt, check the salinity with a refractometer, put in a heater and a pump then let it sit for at least 24 hours, double check temp & salinity before changing 10g for our 90g tank. our ph is usually around 7.8/7.9. corals & fish have done fine. i wondered why our ph was never at 8.3, so i tested the ro/di water and the ph of that was low. after the salt was added, heated & circulated for 24 hours, the ph tests at 7.8. 2 months ago, i started adding ph buffer to the ro/di water before adding it to the tank. we have 130# of live rock, 3" of aragonite sand, a good skimmer, filter sock changed out 2x/week, lights are on timers. what else can i do to raise and keep ph at 8.3 besides adding buffer? i have a powdered buffer that needs to be dissolved in fresh water and also kent buffer and kent calcium. neither seems to make a difference overall. i don't have the stats with me, but i know that our calcium, alk, nitrate/trite, amm and salinity are all in the very good range and have been stable there for over a year.

 

[viper_930]

Post your Ca and alk levels when you get the chance. The buffer adds to the alk and can be a problem if it's not watched carefully. You may not even need to add the buffer.
Take a cup of water from your tank and stick it outside for 15 minutes. Then test the pH. The cause for low pH is often excess CO2 building up in the water.

 

[bang guy]

I addition, when you add the salt to the RO/DI water to make saltwater make sure you pour it in slowly and stir it vigerously. You need the trace elements in the salt to dissolve as fast as possible in cool water.
Adding buffer to RO/DI water is unneccessary and can actually make it even more difficult to properly dissolve the Calcium chloride in the salt mix.
If you are doing a very large water change and the alkalinity of the new saltwater is low then it's OK to add buffer after mixing the salt, not before. If the Alkalinity isn't low then don't add buffer.
It's far more effective to dose your display tank though. Again, only if alkalinity is low. Don't ever add buffer when Alkalinity is already at a good level.

 

[aztec reef]

Don't try the band-aid solution.
The problem is not in the newly made water, the problem is in your tank and how it reacts to this imbalances.
calcification in corals is dependent on ph levels. meaning; low ph= low calcification process. that means that some nutrients/calcium is not being used.
Also if Alk is not supplemented as fast as it is removed by calcification the PH will drop. Phosphates is known to precipitation of calcium carbonate, it also decreases calcification in corals.
If excess CO2 is the issue, I would first do a Large water change, then drip- add limewater(to replenish water evapor) & bring alk/ ph/calcium within recomended levels.(not to mentione kalkwasser removes excess CO2) once this levels team up within range, you can start adjusting calcium/ph/alk if needed. and just maintain with limewater or a 2part additive when needed. Other than that there's no need for any supplements or buffers to newly made water, or to the DT unless you have a high amount of corals with high demands.

 

[smokingreefer]

Originally Posted by Bang Guy
http:///forum/post/2644033
I addition, when you add the salt to the RO/DI water to make saltwater make sure you pour it in slowly and stir it vigerously. You need the trace elements in the salt to dissolve as fast as possible in cool water.
Adding buffer to RO/DI water is unneccessary and can actually make it even more difficult to properly dissolve the Calcium chloride in the salt mix.
If you are doing a very large water change and the alkalinity of the new saltwater is low then it's OK to add buffer after mixing the salt, not before. If the Alkalinity isn't low then don't add buffer.
It's far more effective to dose your display tank though. Again, only if alkalinity is low. Don't ever add buffer when Alkalinity is already at a good level.

Ya if you think about it, even if you do add buffer to the new water, it is barely over 10% of the water for the DT. So if you dose it and not the DT, you aren't going to see the increase you are expecting. In reality you are actually dosing as if the aquarium were only 10 gallons and not 90.

 

[kirkland]

Thanks, this does help me understand better. I remember reading somewhere a lot of people stating that water changes need to be heated and salted for 24 hours for the ph to be correct but that didn't seem to be happening in our tank and an oceanographer told me that wasn't how ph works. I just did a 10% water change yesterday. I'll test the water tonight or tomorrow and will post the results for calcium, ph and alk. I'll also put a cup of water outside then test the ph to see if there is any difference.

 

[kirkland]

Finally had time to test water today. Ph is 8.15, Calcium is 305 and Kh is 13.28. We're almost finished up with a large bucket of reef crystals salt but think we'll switch to oceanic because of the low calcium.
Maybe this should be in a separate thread, but I need to dose calcium. Can I add the Kent liquid calcium alone without adding the Pro buffer dKH?

 

[bang guy]

Originally Posted by kirkland
http:///forum/post/2658102
Can I add the Kent liquid calcium alone without adding the Pro buffer dKH?

Yes, only dose what's low. I'm glad your tank is coming together.

 

[reefreak29]

Just To Add My .02 , Ive Been Doing This For Some Time Now And My Ph Has Always Been 7.8 ,never Added Anything To Bump It Up And 8my Corals Have Always Done Fine

 

[kirkland]

Originally Posted by reefreak29
http:///forum/post/2659199
Just To Add My .02 , Ive Been Doing This For Some Time Now And My Ph Has Always Been 7.8 ,never Added Anything To Bump It Up And 8my Corals Have Always Done Fine
our ph was low for almost the entire 1st year it was up. it's been 14 months now and the ph is up from the 7.8/9 it had been, now around 8.1 is the average. i haven't seen a bad effect from the low ph, the only corals we've lost were a hammer due to gbta attacked it and xenias that i couldn't get attached. i notice the ph a lot since getting the electric ph monitor hooked up to our reefkeeper.