Chronic low PH.

oldschoolbeginner · Dec 17, 2021

I have 2 reef tanks one (90gal) is 2 months old with stable ph and the second is over a year old (55 gal). 55 gal Parameters are
alk 9.2
Calcium 456
Magnesium 1300.
(Before anyone laughs…) this is supported on canister filter.
The issue that I have is that my PH is not even close to stable. While I expect to have some swing from morning to night. But to the extent of 8.24 as a high to 7.75 when when the lights first go on. This issue just started about 2 weeks ago. Other parts include .. aqua ultraviolet 2000+ UV(100% of the water goes through it), aqua max hob 1.5 skimmer and recently resorted to an air stone connected to a medical grade oxygen tank( this only slightly raises the PH). Water changes are done through Neptune DOS via auto water change, this is 6 gallons per week. Fish appear happy and healthy full color corals appear ok but the inverts (carbs and snails) seem lethargic.
Is there any ideas to reduce the swing and stabilize the tank before I crash it.

SlugSnorter · Dec 17, 2021

oldschoolbeginner said:
I have 2 reef tanks one (90gal) is 2 months old with stable ph and the second is over a year old (55 gal). 55 gal Parameters are
alk 9.2
Calcium 456
Magnesium 1300.
(Before anyone laughs…) this is supported on canister filter.
The issue that I have is that my PH is not even close to stable. While I expect to have some swing from morning to night. But to the extent of 8.24 as a high to 7.75 when when the lights first go on. This issue just started about 2 weeks ago. Other parts include .. aqua ultraviolet 2000+ UV(100% of the water goes through it), aqua max hob 1.5 skimmer and recently resorted to an air stone connected to a medical grade oxygen tank( this only slightly raises the PH). Water changes are done through Neptune DOS via auto water change, this is 6 gallons per week. Fish appear happy and healthy full color corals appear ok but the inverts (carbs and snails) seem lethargic.
Is there any ideas to reduce the swing and stabilize the tank before I crash it.

are you sure your not overfeeding? what are you testing it with?

jda · Dec 17, 2021

Before you chase pH at all, make sure that whatever you use to test it is accurate - pH probes are some of the most unreliable and short lived pieces of equipment in the hobby.

Next, the ambient co2 in the air in your home is the number one reason the pH will be what it is. Get fresh air in your home and see what a difference it makes - I am not talking about cracking a window an inch for a few hours, but like actually using something mechanical to turn it over many times on all levels. Some folks don't do the basement and then when they turn their AC or heat back on, it mixes all up again. In any case, some work here and even a $20 box fan for a window usually is your best way forward. You can always find a nice day or two a week if you want to.

If you still don't like it, reverse light cycle fuges have worked for decades to keep night time pH higher. You can use some kalkwasser if you think that you can handle the cons and risk of crash if misused. Some use soda ash reactor to help - effectiveness again depends on ambient air. Some bring a fresh air line into their skimmer.

FWIW - I had tanks in Missouri with night time pH in the 7.75-8.05 range when we could not open up the house to air it out. Everything was fine. Once we could get some windows open and attic fan turned on, it went to like 8.0-8.25 range overnight. I did not notice much difference either way. I eventually got to where I only keep a pH pen and check it only when helping people on the internet. I have no idea what my pH is right now nor for a year.

oldschoolbeginner · Dec 17, 2021

SlugSnorter said:
are you sure your not overfeeding? what are you testing it with?

I am using Hanna checkers for ph,alk, and calcium. Red Sea tester for magnesium. Feeding is done via Neptune afs and feeding with BRS pellets. Every other day with Red Sea AB+ Coral food.

oldschoolbeginner · Dec 17, 2021

jda said:
Before you chase pH at all, make sure that whatever you use to test it is accurate - pH probes are some of the most unreliable and short lived pieces of equipment in the hobby.

Next, the ambient co2 in the air in your home is the number one reason the pH will be what it is. Get fresh air in your home and see what a difference it makes - I am not talking about cracking a window an inch for a few hours, but like actually using something mechanical to turn it over many times on all levels. Some folks don't do the basement and then when they turn their AC or heat back on, it mixes all up again. In any case, some work here and even a $20 box fan for a window usually is your best way forward. You can always find a nice day or two a week if you want to.

If you still don't like it, reverse light cycle fuges have worked for decades to keep night time pH higher. You can use some kalkwasser if you think that you can handle the cons and risk of crash if misused. Some use soda ash reactor to help - effectiveness again depends on ambient air. Some bring a fresh air line into their skimmer.

FWIW - I had tanks in Missouri with night time pH in the 7.75-8.05 range when we could not open up the house to air it out. Everything was fine. Once we could get some windows open and attic fan turned on, it went to like 8.0-8.25 range overnight. I did not notice much difference either way. I eventually got to where I only keep a pH pen and check it only when helping people on the internet. I have no idea what my pH is right now nor for a year.

I did go after the “fresh air” concept but that did nothing to change it. That is when I resorted to an oxygen tank. Not sure that lack of oxygen is the issue. That is why I was looking for other ideas.

glency · Dec 17, 2021

jda said:
Before you chase pH at all, make sure that whatever you use to test it is accurate - pH probes are some of the most unreliable and short lived pieces of equipment in the hobby.

Right when I read this my phone notification from the APEX system alarmed "low ph.' Hahah. I don't trust it either.

nereefpat · Dec 17, 2021

oldschoolbeginner said:
I did go after the “fresh air” concept but that did nothing to change it. That is when I resorted to an oxygen tank. Not sure that lack of oxygen is the issue. That is why I was looking for other ideas.

Oxygen has no effect on pH.

Are you measuring with a probe that has been recently 2 point calibrated with 7.0 & 10.0?