• Welcome back Guest!

    MARSH is a private reefing group. Comments and suggestions are encouraged, but please keep them positive and constructive. Negative threads, posts, or attacks will be removed from view and reviewed by the staff. Continually disruptive, argumentative, or flagrant rule breakers may be suspended or banned.
  • Hello Guest,

    How would you like to get a Build Thread Contributor title/badge?
    Go here for instuctions.

Low pH? (1 Viewer)

SCUBAFreaky

Enjoy Life!
Supporting Member
MARSH Secret Santa 2020
Build Thread Contributor
Joined
Apr 14, 2020
Messages
203
Reaction score
257
Location
Seabrook
To my horror I recently discovered that my pH probe had slowly drifted high by 0.5 pH. I have an Apex with a single junction BRS probe. I recalibrated the probe but now I'm stumped that my pH daily range is 7.8 to 8.0 instead of the target 8.1 to 8.3 that I thought I was maintaining. I run alkalinity around 9.0. Calcium around 450. Magnesium around 1500. I use BRS 2 part. I also run a skimmer with dryer skimmate.

Nothing in my house has changed that I know of. No new pets. No new occupants. No new changes in who works from home or not. I do not have a gas furnace.

I've been struggling for months with zoa deaths and poor polyp extension from my SPS. In the last month the zoas that have survived are doing better but still don't have healthy polyp extension. It would be great (and crappy for that matter) if one of my biggest problems was indeed low pH when I didn't know it.

But here's my problem. Why is my pH now averaging 7.9 instead of 8.2 with no changes in CO2 contributors? What else besides elevated CO2 would keep my pH on the lower side assuming a stable alkalinity of 8.5 to 9.0?
 

webster1234

Supporting Member
Joined
Jun 29, 2012
Messages
1,342
Reaction score
615
Location
Pearland
You could always try a CO2 scrubber and see if that makes a difference. I have a home made one here that I'm not using if you want to come get it. I also have about 5g of media for it.
 

PorpoiseHork

Supporting Member
MARSH Secret Santa 2020
Build Thread Contributor
Joined
Apr 20, 2017
Messages
782
Reaction score
259
Location
Spring Branch
Have you verified the PH reading is accurate? Try testing the PH with a third party test kit to see. There is a chance that it's still slightly out of calibration. If a test kit confirms the APEX is reading correctly, then one of the main things you can do to increase the PH is increase surface agitation to promote gas exchange. If you're running a fuge you can try thinning out the macro and increasing the photo period for it as well to 12-14 hours. You can also add a vent fan to the tank stand as well. I attached a 120mm 120v vent fan on one end of the stand and have it connected to my fuge light timer. So every night when it kicks on as the main lights are shutting down, the cabinet gets vented and the skimmer has a constant supply of fresh air. As a result my PH is always 8.1-8.2 and never fluctuates outside of that range.
 

davidrod8

The Patio Reef Tank
Build Thread Contributor
Joined
Jan 27, 2020
Messages
62
Reaction score
117
Location
Katy, Texas
+1 on surface agitation. How about your skimmer? Any changes there lately? Maybe take advantage of the nice weather we are having and open up some windows. See if that helps.
 

Tenny

Supporting Member
Build Thread Contributor
Joined
Jul 18, 2018
Messages
759
Reaction score
623
Location
League City
Have you verified the PH reading is accurate? Try testing the PH with a third party test kit to see. There is a chance that it's still slightly out of calibration. If a test kit confirms the APEX is reading correctly, then one of the main things you can do to increase the PH is increase surface agitation to promote gas exchange. If you're running a fuge you can try thinning out the macro and increasing the photo period for it as well to 12-14 hours. You can also add a vent fan to the tank stand as well. I attached a 120mm 120v vent fan on one end of the stand and have it connected to my fuge light timer. So every night when it kicks on as the main lights are shutting down, the cabinet gets vented and the skimmer has a constant supply of fresh air. As a result my PH is always 8.1-8.2 and never fluctuates outside of that range.


If you have an Apex 832 EnergyBar you can just buy a 24v fan also. Good idea though, I hadn't thought about that. My tank is always low on the PH side.
 
OP
SCUBAFreaky

SCUBAFreaky

Enjoy Life!
Supporting Member
MARSH Secret Santa 2020
Build Thread Contributor
Joined
Apr 14, 2020
Messages
203
Reaction score
257
Location
Seabrook
Have you verified the PH reading is accurate? Try testing the PH with a third party test kit to see. There is a chance that it's still slightly out of calibration.
Actually, I have not verified that the recal was accurate. I do have a stand alone Milwaukee probe that I can calibrate and get a second reading from. You're right, I shouldn't put so much faith in the Apex and BRS probe calibration.

If a test kit confirms the APEX is reading correctly, then one of the main things you can do to increase the PH is increase surface agitation to promote gas exchange. If you're running a fuge you can try thinning out the macro and increasing the photo period for it as well to 12-14 hours. You can also add a vent fan to the tank stand as well. I attached a 120mm 120v vent fan on one end of the stand and have it connected to my fuge light timer. So every night when it kicks on as the main lights are shutting down, the cabinet gets vented and the skimmer has a constant supply of fresh air. As a result my PH is always 8.1-8.2 and never fluctuates outside of that range.
As far as gas exchange goes I do run a skimmer and my overflow is an old school Durso drain...I set up the tank long before I learned who Herbie was and what a bean animal might be. My sump does indeed have a fuge but I'm not growing any macro algae due to running an Algae Turf Scrubber instead. That said the fuge has a slight waterfall as it flows to the return pump chamber. Nonetheless I've never considered that I wasn't getting enough gas exchange with all of places that the water gets turned over and exchanged with air. Putting a fan in my sump area is an interesting idea and certainly worth a try.

+1 on surface agitation. How about your skimmer? Any changes there lately? Maybe take advantage of the nice weather we are having and open up some windows. See if that helps.
As just mentioned above I do run a skimmer and no changes have been made. And great minds think alike. I work from home and with the weather being awesome I had the windows and doors open both Monday and Tuesday. So far no significant increase in pH.

Alright, thank you for all of the brainstorming. I need all of the recommendations I can get. keep 'em coming for that matter! I will try installing a fan in my sump area and I'm going to borrow a CO2 scrubber from @webster1234 to see if that makes any impacts. But keep the suggestions coming. I've been in the "I'm frustrated with my tank" phase for 6 months now so any help is much appreciated.
 

chrisfoos

Supporting Member
Joined
Apr 25, 2018
Messages
133
Reaction score
135
Location
Katy, TX
What are your nitrates at? When was the last water change? What is your stocking like?

If we assume the PH measurement is correct and the level is caused by CO2, you should look at CO2 users and producers in addition to gas exchange. If you have a lot of fish and no place for algae to grow you are going to have more CO2 producers than users and will need high gas exchange. There is also the chance that if you have high nitrates you could be supporting a large amount of bacteria that uses O2 and nitrates to make CO2.
 

PorpoiseHork

Supporting Member
MARSH Secret Santa 2020
Build Thread Contributor
Joined
Apr 20, 2017
Messages
782
Reaction score
259
Location
Spring Branch
Get yourself a standard off the shelf PH test kit such as API or something. It really does not have to be anything super fancy, just one to use to compare against the APEX.

If they are not already, aim the return(s) in the tank to the surface. This will break up the tension across the top of the tank over a much larger area than just what takes place in the skimmer/sump. You can also connect a longer host to the skimmer venturi and run it outside the stand so it has a constant supply of fresh air. If there's a window close you could even try running it outside the house. Just be sure to put a filter on it to prevent bugs from going in it.
 
OP
SCUBAFreaky

SCUBAFreaky

Enjoy Life!
Supporting Member
MARSH Secret Santa 2020
Build Thread Contributor
Joined
Apr 14, 2020
Messages
203
Reaction score
257
Location
Seabrook
What are your nitrates at? When was the last water change? What is your stocking like?
To my surprise after I did my last water change my nitrates were 27 ppm. I've been running an algae turf scrubber for the last year and my nitrates had been running near zero or slightly above. I find it odd that my nitrates are this high. I stopped checking it since it was always close to near zero. I've also noticed that my scrubber doesn't produce the same type of algae it did in the first 6 months and it also doesn't produce algae near as fast as well. Instead of cleaning the screen every 7 to 10 days I'm going 3 weeks to a month right now. I did a 50% water change 2 weeks ago which is what alarmed me to having a drifting pH probe. The pH spiked to over 8.5 when I did my water change with a batch of salt with 7 previous water changes so I knew the probe was off. My tank (72 gallon bowfront) has a full stock of fish. Two clowns, 2 damsels, 2 scissortails dartfish, a tang, an angel, a wrasse, and a little bitty neon goby.
If we assume the PH measurement is correct and the level is caused by CO2, you should look at CO2 users and producers in addition to gas exchange. If you have a lot of fish and no place for algae to grow you are going to have more CO2 producers than users and will need high gas exchange. There is also the chance that if you have high nitrates you could be supporting a large amount of bacteria that uses O2 and nitrates to make CO2.
If the cal on the probe isn't exact it's pretty close. Before I ran the cal I split the 7.1 solution and the probe read 7.5. After the cal my daily swing dropped by 0.5. So it's gotta be close to accurate but I will acquire a way to double check the BRS probe over the weekend. So I do have a lot of fish but with the vented Durso overflow drain into a sock filter, the skimmer and the sump water fall I should have a lot of gas exchange. This is a very interesting notion about high bacteria. Can you explain this further?
 
OP
SCUBAFreaky

SCUBAFreaky

Enjoy Life!
Supporting Member
MARSH Secret Santa 2020
Build Thread Contributor
Joined
Apr 14, 2020
Messages
203
Reaction score
257
Location
Seabrook
Get yourself a standard off the shelf PH test kit such as API or something. It really does not have to be anything super fancy, just one to use to compare against the APEX.
I hope to get pH test kit this weekend.
If they are not already, aim the return(s) in the tank to the surface. This will break up the tension across the top of the tank over a much larger area than just what takes place in the skimmer/sump. You can also connect a longer host to the skimmer venturi and run it outside the stand so it has a constant supply of fresh air. If there's a window close you could even try running it outside the house. Just be sure to put a filter on it to prevent bugs from going in it.
I am going to borrow a CO2 scrubber this weekend. This should tell us if this a high CO2 problem or not. I am very curious about running the scrubber. Kinda excited actually.
 

chrisfoos

Supporting Member
Joined
Apr 25, 2018
Messages
133
Reaction score
135
Location
Katy, TX
Bacteria suggestion is an idea I threw out there to highlight there are other things that impact O2/CO2. One of the big issues we have is farm runoff, nitrates and phosphates, causing bacteria blooms in the ocean that use up all the O2 killing things. Not saying you have a "bloom" but high nitrates could support larger colonies of things like bacteria that use O2 and produce CO2.

If your nitrates are high but your scrubber is not producing, you could be low on something else algae needs to grow. If your algae is not growing that could be causing lower ph as well. When we have our lights on during the day and the ph goes up, that is algae growing. Check your phosphates, iodine, and iron if you can. There may be more things algae needs but those are the main ones I'm aware of that it needs to grow. One of these being low could also cause poor coral health. You did say your zoa's rebounded a bit, was that after a water change? If so, I would do several large water changes over a week and see how that works out. That is quicker than an ICP test and has no real downside.

Another thing you can do fairly quickly is get a GFCI cord and a ground probe. Put all your equipment through the GFCI and the probe in the water. GFCI needs a good path to ground and most stuff we use is two prong so you need that ground probe. If it trips, you have something that is damaged and shorted to the water that you need to figure out and replace. Electrical current in salt water turns chloride to chlorine which dissolves back into the water and that is known as bleach.
 
OP
SCUBAFreaky

SCUBAFreaky

Enjoy Life!
Supporting Member
MARSH Secret Santa 2020
Build Thread Contributor
Joined
Apr 14, 2020
Messages
203
Reaction score
257
Location
Seabrook
If your nitrates are high but your scrubber is not producing, you could be low on something else algae needs to grow. If your algae is not growing that could be causing lower ph as well. When we have our lights on during the day and the ph goes up, that is algae growing. Check your phosphates, iodine, and iron if you can. There may be more things algae needs but those are the main ones I'm aware of that it needs to grow. One of these being low could also cause poor coral health.
I've suspected for a while that there is something missing in my water affecting how the Algae grows, that's impacting SPS polyp extension and my zoa health. When my tank started showing signs of trouble in October I did several ICP tests. Iodine was on the low side. 0.03 ppm. I dosed for a while and never saw any real change so I stopped. I also dosed trace elements for a while as well and never saw any real improvement there either. Phosphates are above 1 ppm so I'm trying to get those down with water changes. Iron was zero in the ICP but I thought that's where you want iron. That's at least what the ICP test indicated that the target should be. I think if I can figure out what's missing in my water, that will solve a lot of my problems.
You did say your zoa's rebounded a bit, was that after a water change? If so, I would do several large water changes over a week and see how that works out. That is quicker than an ICP test and has no real downside.
The zoas rebounded by me not doing any water changes or any chemical additions other than Alk for a couple of months. When I discovered that my phosphates were high I did a 50% water change 2 weeks ago and didn't see any change in coral health all around. Those corals that were happy stayed happy and those that are not as happy stayed unhappy. I'm actually starting up weekly 25% water changes again. I've got one ready for tomorrow in fact.
Another thing you can do fairly quickly is get a GFCI cord and a ground probe. Put all your equipment through the GFCI and the probe in the water. GFCI needs a good path to ground and most stuff we use is two prong so you need that ground probe. If it trips, you have something that is damaged and shorted to the water that you need to figure out and replace. Electrical current in salt water turns chloride to chlorine which dissolves back into the water and that is known as bleach.
I love all of your brainstorming ideas! This is exactly what I need from folks to try to sort all of this out. I've been fighting an all around tank issue for 6 months now. Okay, I like where your head is at. When I set up the tank 11 years ago I swapped out the outlet with a GFCI outlet and installed a titanium grounding probe in the display tank. So this one has been done already.

What else can you think of? Definitely keep those ideas coming!!
 

Users who are viewing this thread

Top