Really Need Help with PH and KH

[bencc]

I'm affraid I'm screwing up the cycle on my new tank. I recently set up a new tank with live rock and live sand. The ph has been low and I have been buffering with seachem reef buffer 8.3. The ph will come up to 8.2 then slowly go back down over the course of about 4 to 5 hours to 7.7. I'm using a digital ph monitor that I calibrated last night so I know it is correct. The crazy thing is my KH is very high. It is at like 18 drops. I am using premixed ro saltwater from the LFS. The premixed water is at about 10 drops kh and 7.6 ph. So I'm now doing water changes to try to get the KH back down. I'm worried I'm screwing up the cycle. The rest of the readings are below. Anyone have any idea why the KH would be so high and the ph so low
Calcium - 420
PH - 7.7
KH - 18 drops
Salinity 1.024
Amm, Nitrite, Ntrate- 0 because cycle has not started

 

[tropills]

are you noticing the drop with the lights on or off, pH will drop when the tank lights are off, what type of salt is you LFS using? consider getting a small bag of salt and a few gallons of water from walmart or something and mix your own mix then test and see what you have.

 

[earlybird]

I would not worry about pH while cycling. The only things to check for while cycling your tank are ammonia, nitrite, nitrate, and your salinity or specific gravity. Also, as you add buffer you are increasing your alkalinity which screws with your calcium and magnesium. Not sure what 18 drops equates to but you shouldn't have to worry at this time.

 

[bencc]

The KH of the saltwater mix I am using is about 10 drops sorry I'm not sure what that breaks down to but normal is from 9-12 drops. The Ph of the saltwater mix is 7.6. I have been reading that a gas fire place in the house can cause a drop in ph due to a low o2 level. I recently did get a propane fireplace. This ph reading really doesn't change much with lights on or off.

 

[jasonmarc]

I'll ask before someone else does - do you have a glass top or other issue that may interfere with gas exchange? What kind of turnover do you have in your tank? It seems low pH can be caused by, as you said, lower O2 levels... so let's see if that's the cause.
And 18 drop (assuming you're using like the API test kit) comes out to 322 for your alkalinity. Way high - to the point of being detrimental to any life you want to put in there.
However, I'd get your cycle going anyway and figure out the pH and alk problems as you go along. Your alkalinity will gradually lower, but it might take a couple of water changes after the cycle to do it fast enough for wanting to put in fish, or whatever...
hope that helps initially!
Jason

 

[bencc]

No glass top it's a 12g nano. I have plenty of water circulation. I upgraded from the stock pump to a maxi jet 900 and have the original powerhead in the tank moving water. This kh thing really is a mystery to me. I should be getting my protein skimmer at the end of this week. That should rule out the low o2 theory if the PH stays at 7.7 with the protein skimmer. I just wanted everything to be as good as possible in the tank to keep as much life in the rock and sand as possible during the cycle. When I had this tank running before I never had a problem maintaining a ph of about 8.2.

 

[ibew]

Originally Posted by bencc
No glass top it's a 12g nano. I have plenty of water circulation. I upgraded from the stock pump to a maxi jet 900 and have the original powerhead in the tank moving water. This kh thing really is a mystery to me. I should be getting my protein skimmer at the end of this week. That should rule out the low o2 theory if the PH stays at 7.7 with the protein skimmer. I just wanted everything to be as good as possible in the tank to keep as much life in the rock and sand as possible during the cycle. When I had this tank running before I never had a problem maintaining a ph of about 8.2.

like stated before you shouldn't be testing for nothing until the water cycles than after you read
nitrite 0
nitrate 0
amionia 0
than your tank is cycled you can start adjusting your alk calcium and mag and your PH
also if your mag isn't around 1350 your going to have a hard time keeping a stable alk and cal and PH

 

[kirkland]

Originally Posted by Ibew
also if your mag isn't around 1350 your going to have a hard time keeping a stable alk and cal and PH

(butting in here) i didn't know this. our ph is staying around 7.9 and our kh is just slightly under normal levels but all other levels are spot on. should i get a magnesium test kit? if so, can you recommend a good one? i haven't been able to get our ph to stay above 8 yet everything appears healthy/normal.