Help with fluctuating PH

[CSJIII]

I have a 28 gal. JBJ nano with a 150W halide that has been up and running for 2 years. All of my corals, chalices and zoas mostly, have been growing very nicely, but since I got my Apex lite, I have been closely monitoring my PH and temp in attempt to maybe get my corals to grow even better. As you can see in the images below, my PH mirrors my light cycle. The graph clearly shows that when my lights come on, PH increases, lights go off....immediate decrease. I have been dosing a 2 part Reef Code A and B from Brightwell and can be referenced in the photo as the spike in PH at aprox 11:45 last night as seen in the first photo. What should I be looking for in attempt to keep the PH steady? My levels are as follows, all tested with water taken from tank just before lights went off which means, high PH.

Salinity--1.027
KH--6
Calcium--420
PH--fluctuating
Ammonia--0
Nitrite--0
Nitrate--trace
Magnesium--1300

 

[mrsmithers]

Your alk or dKH should be higher and this will help with the swings. pH swings are normal with lighting but a proper buffered system handles them better. You could look into a reverse lighting refuge which will combat the pH drop.

 

[CSJIII]

Your alk or dKH should be higher and this will help with the swings. pH swings are normal with lighting but a proper buffered system handles them better. You could look into a reverse lighting refuge which will combat the pH drop.

Ok. I did take a look at some of the small external sumps in thought of that helping tweak my system. How about a kalk drip?

 

[agent462]

Your Alkalinity level is definitely contributing to the problem. A higher Alkalinity will cause a smaller PH swing. Additionally you're probably having a Carbon Dioxide problem now that your house is nice and closed up for the winter.

You're going to want to dose Sodium Carbonate to get your Alk back up. You can then maintain with a Kalkwasser drip. If you have a more severe Carbon Dioxide problem, you'll be fighting it more.

 

[jonzee2006]

+100 on the dkh thats what helps keep it steady it should be in the 8-10dkh range.

 

[jonzee2006]

by the way take your time raising your alk it should be done over the course of a couple of days

 

[Paul_N]

+1 to raising the alk like everyone else said. A kalk drip will definitely help keep the PH up while the lights are off. Just make sure you adjust your 2 part dosing also for the Ca since the kalk will be adding that also.

 

[Murfman]

Make sure you calibrate your pH probe every couple of months too. I extended my skimmer intake hoses so they can go outside via the window. This pulls in fresh air from the outside and not CO2 laden air that settles in the basement, where the tank is.

 

[CSJIII]

I have known my KH is low for some time. I tried adding Kent buffer a while ago but wasnt able to get it up very high. Why might my KH be low and how do I get it up to acceptable levels safely?

 

[Murfman]

What are your magnesium and Calcium levels?

 

[beaslbob]

Baking soda will raise alk nicely.

I would look up the diy two part which is very similiar to the two part dosing but the entire article may help explain the whole process.

FWIW in tank where the plant life (algaes macros etc) if fully consuming carbon dioxide you will get the pH rise with lights on. Without the macros/algaes the pH would stay more constant but at much lower levels. Because the co2 is not being removed as well.

So to me the important thing is first what is the pH just before lights out. and secondly is alk 8-9 dkh or so.

my .02

 

[Murfman]

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com

 

[CSJIII]

What are your magnesium and Calcium levels?

Look above

 

[Murfman]

Look above

Sorry. Bring your mag up to 1450-1500.

 

[swannyson7]

In addition to adjusting alk (which is the ultimate solution) try running a light over your sump in a reverse photoperiod to keep your pH up at night. You could also run an air pump bubbling in your sump at night to help disolve the CO2 and keep your pH up.

 

[AZDesertRat]

I would not concern myself with pH, you can chase it all over until you die. It is what it is and as long as you maintain the other levels where they should be it will balance itself out accordingly. It is going to fluctuate and there is nothing you can do to correct that, not that it needs correcting anyway. I do light my refugium on an opposite schedule from my display and that does help somewhat but I don't really worry about it.

 

[CSJIII]

I run my lights for about 8 hours....seeing that the ph is highest just before The lights go out....what would happen if I had my lights on for 10 hours? Would the ph keep going up?

 

[beaslbob]

I run my lights for about 8 hours....seeing that the ph is highest just before The lights go out....what would happen if I had my lights on for 10 hours? Would the ph keep going up?

No. What happens IME is pH quickly rises then levels off after lights on. After you essentually got the carbon dioxide out, the pH stops rising. And that doesn't take more a few hours at most.

Actually pH could rise if the plant life (algae/macros) has not fully removed the co2. But after that point a few extral hours will not make much differenct.

 

[HighlandReef]

Offhand not sure what kind of lighting you have but I personally would not run the lights longer
I would 1st fix your alk, too low
I run my system at 8 dkh
If you fix you alk your ph will most likely fall in line
I would be more concerned about you alk than ph, ph will swing its normal, photosynthesis.

 

[CSJIII]

Offhand not sure what kind of lighting you have but I personally would not run the lights longer
I would 1st fix your alk, too low
I run my system at 8 dkh
If you fix you alk your ph will most likely fall in line
I would be more concerned about you alk than ph, ph will swing its normal, photosynthesis.

It was more of a hypothetical question that if I left my lights on longer, would the ph keep going up or would it top off at some point.