High Ca, 21.5 dKH, pH 7.76-7.95 need help

[z3r0ko0l]

I recently installed my Apex Reef computer on my 75g mixed reef system w/euroflo 20g sump. After calibrating my probe I saw that my pH was on the lower end 7.6 and was concerning me. Thinking the new Probe was bad (BRS probe, tested before it was mailed), I tested with my kits. "fasTest," by aquarium systems, "pH/alkalinity" by red sea and KH by API. the pH reading I was getting where in the 7.8-8.0 range. So I wanted to make sure the probe was right and ordered two new batches of calibration fluid. The first set is also new but in packets (pinpoint 7 and 10), the second set ordered are in the large bottles from Marine Depot (7 and 10). Once they arrived I calibrated the probe again and it calibrated the same. I then placed it in the tank water (after rinsing) and let it sit. Once again the pH went to 7.6. I then placed the probe in a fresh packet of 7.0 calibration fuild to see what the probe would read. It went to 7.0 dead on. Now I knew the probe was right I started to adjust the pH. I have Kent Marines "super buffer and over about a week used 7 oz. trying to maintain at least a pH of 8. I then did some reading figuring Superbuffer was Sodium Bicarbinate I realized I was probably attacking the Alk or then the pH. I switched to Sodium Carbinate (BRS soda ash) to get the pH up. That did the trick, but my corals, especially the LPS are not extenting as much. Back to testing. My pH is now 7.76 at its lowest at night and 7.95 during the day at its highest. My dKH is 21.5! So I read in "The Reef Aquarium" Vol. 3 that this will usually cause Ca to drop and to add Calcium Chloride to raise Ca. and force the Alk. to drop fixing my problem. I then tested the Ca and I stopped when it was over 650! Im not sure what to do next. I changed 10g of water and am prepareing another 10g. Any Ideas? Also, I uncovered the tank, added a fan to the sump and opened the windows trying to eliminated a high C02 problem. "The Reef Aqurium" book says that if the tanks Alk and Ca are both high to do nothing at this point and the problem will correct itself with time. My concern is are these levels to high? I really dont want to see my corals die off. On a side note my 5 fish all seem to be doing well.

Tank Params.
Tank Size 75g + 20g sump (120+lb live rock 100lb sand)

Sg 1.025
Ca +650
pH 7.84 (3 hrs into light cycle)
KH 21
Mg 1340

 

[bertoni]

Using pH buffers to fix pH problems often causes this problem. I'd stop dosing calcium and alkalinity, and let the levels settle. It's very difficult to force down alkalinity by dosing calcium, because the calcium level generally needs to be very high for that to happen, well above 650 ppm. If any animals are in trouble, I'd do some water changes.

The cause of low pH in an established tank always is carbon dioxide:

http://reefkeeping.com/issues/2004-09/rhf/index.htm

It's possible that the meter is having some problems with electrical interference. I'd try measuring a cup of water well away from the tank. If you're using an AC adapter for the meter, I'd plug it into a separate circuit from the tank. Once we eliminate electrical interference, if any, we can look at the pH problem more, but low pH levels are very common in tanks when they're closed up for the winter or summer.

 

[paulduong]

i would do 20 % water change , go to lfs and find some chemical to raise ph without raising kh .

 

[bertoni]

It's impossible to raise the pH without raising alkalinity when using an additive. Reducing the carbon dioxide level is all we can do.

 

[z3r0ko0l]

I stopped Kalk drip a few days ago after I checked the dKH and Ca levels. Ive also been opening windows at night trying to reduce the possibility of a C02 problem. My air conditioner and chiller are hating me for it. Im thinking of running the air line from the skimmer out the window for fresh air. I going to continue the water changes till my levels come back in line. My main concern is my corals and fish. Fish are looking fine and acting normal, only thing that is apparent are my LPS are not extending as much.

Thanks for the link, that article looks to be verbatim form the book. Same charts and everything. Im just concerned that the levels are so high that I should be doing something proactively to solve the problem.

 

[duramax]

i would do a big water change like 50% and don't dose any alk for awhile, i have had that problem before and it takes a little while to lower your alk, thats the bad thing about ph buffers most also raise your alk

 

[bertoni]

All pH buffers must raise alkalinity, basically by definition. They are just high-pH alkalinity supplements.

 

[KrazyReef]

Something doesn't make sense. Alkalinity and PH go hand-hand together. I don't think it's possible to have 21 dkh and ph at 7.8 prefering to the chart in http://reefkeeping.com/issues/2004-09/rhf/index.htm

I agree that 20-30% water change is necessary. I would also suggest to stop dosing anything at this time, wait for the water to settle then re-run the tests. I bet the results will be much better unless the tests are not done right.

 

[noobtothereef]

Something doesn't make sense. Alkalinity and PH go hand-hand together. I don't think it's possible to have 21 dkh and ph at 7.8 prefering to the chart in http://reefkeeping.com/issues/2004-09/rhf/index.htm

I agree that 20-30% water change is necessary. I would also suggest to stop dosing anything at this time, wait for the water to settle then re-run the tests. I bet the results will be much better unless the tests are not done right.

yep 21dkh and 7.8 ph is impossible unless your tank is carbonated like a soda pop

 

[noobtothereef]

I stopped Kalk drip a few days ago after I checked the dKH and Ca levels. Ive also been opening windows at night trying to reduce the possibility of a C02 problem. My air conditioner and chiller are hating me for it. Im thinking of running the air line from the skimmer out the window for fresh air. I going to continue the water changes till my levels come back in line. My main concern is my corals and fish. Fish are looking fine and acting normal, only thing that is apparent are my LPS are not extending as much.

Thanks for the link, that article looks to be verbatim form the book. Same charts and everything. Im just concerned that the levels are so high that I should be doing something proactively to solve the problem.

quit chasig numbers and just do a large water change 50% and then do another 50% water change a few days later, and run airline outside for the skimmer, chemically you cannot change the ph, you must inhibit the addition of c02 , your running a calc reactor? maybe your c02 is running to much in your reactor also

 

[bertoni]

I would avoid large water changes unless animals are dying. Large changes can cause more harm than good. Many people ran tanks at 18 dKH for years back in the old days, so the current dKH level might not be an emergency.

 

[zygote2k]

large water changes will only cause more harm than good. stop chasing the numbers too. If your tank grows corals at 7.6 ph and low alkalinity, then let it grow. Just because the standard is 8.3, doesn't mean that your tank has to be there. Same with Ca and ALk. Every tank is different.

 

[Paulca916]

All pH buffers must raise alkalinity, basically by definition. They are just high-pH alkalinity supplements.

+1

I would avoid large water changes unless animals are dying. Large changes can cause more harm than good. Many people ran tanks at 18 dKH for years back in the old days, so the current dKH level might not be an emergency.

+1

Also double check your Alk ,get a new test kit or borrow a friends to do a test.
With the ph reading you get your Alk is double to what is normal.
Pesonally I don't check my PH that often.
I do check frequently and keep my Alk at 9 DKH and when ever a do check my PH it's at 8.3 I check my ph maybe 12 times a year

 

[z3r0ko0l]

the pH is slowly on the rise and after alot of reading, Ive decided to stop chasing the "magic numbers" once things settle. Ill recheck the dKH again tomorrow. Ill post a link to my apex graphs as soon as im back on my computer. Thx everyone.

 

[z3r0ko0l]

Graphs at

http://www.rowelab.com/AquaController/index.php?scope=last24&userid=z3r0ko0l

These forums wouldnt accept the Url for some reason...just copy and paste. Make sure you remove that space in the url it should be "rowelab"

 

[z3r0ko0l]

I need to add make-up water. Ive got a few gallons RO/DI water ready to go in I just wasnt sure how that would effect the situation. On a side note, I put the inlet to the skimmer outside. My pH still seems to be dropping. Got down to the mid 7.6's now. Still just riding it out.

 

[bertoni]

7.6 is low enough that I'm skeptical about the reading. The calibration seems to be fine, but maybe there's some electrical interference. That seems to happen from time to time. I'd also check for a surface film of some sort. Pointing some powerheads at the water surface to get a strong ripple sometimes helps.

 

[z3r0ko0l]

no film on the surface, I just checked the grounding probe, seems fine. Ill check for stray voltage with a meter tomorrow.

 

[bertoni]

You could try measuring a cup of water, well away from the tank, and plug the power cord into a different outlet, too. Batteries are less prone to interference, for that matter.

 

[z3r0ko0l]

I don't have a stand alone meter =( just the Apex. Ill see if I can take a sample down the the LFS and have them take a reading with their meter.

On a side note my pulsing Xenia and Green Slimer dont seem to be extending as much also now.

Also my skimmers skimate is pretty thin looking now with that long 1/4 tubing on it, so I had to adjust it. Since its not getting as much air.