Night and day ph swings

roomclearer · Sep 6, 2014

Ok so I have a 75 bow front all levels are good no3 is 2.5 to 5 ca 440 alk 9.9 to 10.2 mg 1290 to 1300 sg 1.025. I have sps lps and soft n polyps. Claims scallop Roserocks sea at and bubble tip. I dose kalk plus2 in my 5 g top off 2 tsp per 5 gal. My ph slowly rises though day as normal to about 8.26 and I use evergrow lights. Question is at night by morning ph is at 7.96 ish. All livestock is very good looking n happy color etc, is this swing a problem it seems huge? I have reverse lighting in sump with cheato.

Reefing Madness · Sep 6, 2014

Ph is highest after lights go out due to photosynthesis, and its lowest in the morning due to respiration and the buildup of C02.
The “How To” Guide to Reef Aquarium Chemistry for Beginners Part 3: pH by Randy Holmes-Farley - Reefkeeping.com

roomclearer · Sep 6, 2014

Correct but isn't .3 of a change dangerously drastic or is it gradual enough to be ok in your opinion?

Reefing Madness · Sep 6, 2014

No, its not drastic, you'll be ok with that swing, thats just the natural swing of your particular tank, no worries. Everyones will be different.

Randy Holmes-Farley · Sep 8, 2014

I agree that pH swing is fine. It is the bottom of the swing that is more important, IMO, than the swing itself. As long as you are above pH 7.8, it should be fine.

FWIW, the swing will be lessened by more aeration, and complete aeration would eliminate it, unless the CO2 level in your home varied with the time of day.

roomclearer · Sep 8, 2014

Right thanks guys for easing my nerves on it lol. It sometimes goes to 7.95 but more often 8.00 or 8.02 just was worried because everyone says don't let it swing .2 or more in 24 hrs so I thought well **** I'm swing beyond that. But Ty all for your replies I feel better.

pickupman66 · Sep 8, 2014

Randy,

I have been reading alot of PH posts as of late. very interesting. I know not to chase PH as this can lead to bigger issues, but since moving from a tank with a sump in the garage to one completely contained inside the house, I have notice the PH does not like to get out of the 7's. my inhabitants look good for the most part with a few exceptions (too clean of water and didnt feed my acans). I see you mentioned not below 7.8 above. Here is the graph from the last few days for me. some down to 7.75. I have a fuge with lights on when my DT are off. i also have air from the outside piped to my skimmer intake.

mrcoffee2 · Sep 8, 2014

Screen Shot 2014-09-08 at 2.25.12 PM.jpg

I am not sure if it helps but heres my tank PH swing for 4 days. =

Fluctuates between 8.05-8.17

My lights are on 12hrs a day hydras. No other light in the fuge.

roomclearer · Sep 8, 2014

What lights are you using? I use evergrow I think it's the ti40 not sure on that but I also use soda lime in a 2l soda bottle with holes at bottom and air intake from skimmer through the top. That right there and the right lighting gets me at just shy of 8.3 by late afternoon. So I bet anything if your lighting is good than do this with your skimmer but don't get soda lime wet and watch within 2 days you will be in the 8s.

roomclearer · Sep 8, 2014

Also if you know your other peramiters and what effects what etc and understand co2 photosynthesis exchange etc than you can chase ph. There is a huge difference in your coral when ph is up around 8.1 to 8.2. Most people say don't chase it because if you do it wrong your alk will go way up and mess with your corals. My all is between 9 and 10. The only reason my ph is at 8.27 abouts in late afternoon is the right lighting so coral absorbs co2 and produces glucose and oxygen and the soda lime trick.

Randy Holmes-Farley · Sep 8, 2014

pickupman66 said:
Randy,

I have been reading alot of PH posts as of late. very interesting. I know not to chase PH as this can lead to bigger issues, but since moving from a tank with a sump in the garage to one completely contained inside the house, I have notice the PH does not like to get out of the 7's. my inhabitants look good for the most part with a few exceptions (too clean of water and didnt feed my acans). I see you mentioned not below 7.8 above. Here is the graph from the last few days for me. some down to 7.75. I have a fuge with lights on when my DT are off. i also have air from the outside piped to my skimmer intake.

The concern is that as pH lowers further and further into the 7's, corals have a harder and harder time calcifying, and at some pH below 7.7, coral skeletons can begin to slowly dissolve. If the corals seem OK, I wouldn't agonize over it, but the options include limewater (kalkwasser) top off, CO2 scrubber on skimmer air (can be even better than outside air, but is expensive over time) or more fresh air into your home.