water pram questions for sps experts

[jimmystephens]

I have a 120 g mostly sps tank. All sps growing well. Colors decent etc.. my question is my ph stays around 7.9 during the day and 7.6 at night. Cal is 525. Alk is low at 7.8 mag is 1250. (Red sea test kits). Other misc info. Have dual reactor with gfo/carbon. Alk/cal dosing pumps. Weekly 15% water changes. Salinity salt. My question is should i use a buffer daily/weekly to hit ph of 8.3 or dont chase the number?
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Edit: And yes im poss about ph. Have ph probe/reef keeper. Re cal the probe and used test kit to verify.

 

[ralph atl]

Change GFO and Carbon weekly, and up weekly water changes to 20-30% and u are good to go!

Edit: Don't chase PH, as long as you dose Alk...

 

[jimmystephens]

Ok. I change gfo/carbon bi weekly so i try weekly and up water changes. Thanks

 

[darth reefer]

+1 on don't chase Ph, stability is the key not the "magic" number. I would start letting your Ca drop though. That's pretty high. I aim for ionic balance in my tank. Think about it like a cup, if you pour in a bunch of calcium you won't have enough room left to add the proper amount of alk and mag.

 

[outdrsyguy1]

You could try putting some kalkwasser in your ATO if you wanted. Might help with the low ph a little but I agree, don't chase ph. I made the mistake of listening to the LFS and buying buffer and buffered the crap out of the tank but it just kept dropping every day or 2 back to the old levels. ended up screwing up the balance of my tank for atleast a month.

 

[picoreefguy]

im no expert but i think once you get your cal down a little and your mag up (both doable with waterchanges and good salt) it should also help bring your ph up. but as stated before as long as its stable i wouldnt go chasing a magic number

 

[ksicard]

I also think that once you balance out your params your PH might stablilize closer to 8.3. I personally shoot for 440-450ppm Ca, 8.3-8.7DKH, and 1400ppm Mg on my SPS dominant tank. Also using a DKH buffer that also ups PH helps. I also noticed on my tank when I was dosing smaller amounts of my alk supplement such as less than 12ml a day my ph stayed around 7.9, when my alk demand increased and started adding 20ml+ daily my ph tended to run higher due to my alk supplement being dosed more. Now at 45ml a day of alk supplement my PH is it at a stable 8.2-8.3 also running a reverse light cycle on the fuge helps stabilize PH swings. But all in all dont worry about your PH number unless your below 7.8 during daytime. It's more so about keeping it from swinging large amounts over the course of 24 hours.

 

[jimmystephens]

Thanks for the input. Ive been in this hobby for about 10 years on and off. But reefs for only 3 years. I never realized my ph so low till now. Ill cut the dosing pump down on cal and up on alk .

 

[picoreefguy]

and remember to keep doing those water changes. theres nothing better for a tank than a waterchange.