Low PH. Cant keep it above 8.

[eric33014]

So I have a PH problem. It drops. Drops big. From 8.3 to 7.6. I've opened up windows to allow fresh air. I've taken my air intake outside. I have a co2 scrubber. All will go up to 8.3 for a couple days then hover 7.6 to 7.7. I dose alk 2 part. Alk levels are 7.9dkh. I run refugium with alternating lighting schedule to DT. This is a newer apex. I swapped out mid October. Have recalibrated probes 2 times since. I have checked PH with separate PH Hanna checker so apex is reading correctly. I'm dosing alk 14ml daily split between 12 doses. Same with calcium. How can I check or diagnose my problem? Water changes bring up ph again for a couple days then back to low PH. Corals seem to be doing ok except for montiporas and scolys. Trachy goni leathers torches doing great. Any and all help is appreciated.

 

[YankeeTankee]

Sounds like you've tried a bunch of things, how about kalkwasser and or switching bicarb to sodium carbonate?

 

[AquaBiomics]

Just a reminder that on natural coral reefs in the ocean, the pH naturally fluctuates every day from about 7.8 to about 8.1. A lot of reefers are chasing a myth of stable high pH that doesnt occur in the ocean.

 

[walloutlet]

Quick few questions... as I have experienced a similar problem and have been actively working solutions myself in a similar setup that you have described -- 2 part, fuge, CO2 scrubber

1. When your pH gets to 8.3 or it's highest point is that related to when you change out the CO2 media to fresh media? Or strictly just the water change?
2. How big is your water change? Any additives into the fresh saltwater?
3. When pH drops, is it dropping over hours (see screen shot below) or slowly over days?
4. How big is your CO2 media reactor? How often do you change the media?
5. Does your air intake go to your CO2 media reactor? Or are you feeding outside air separately into the tank?

My initial thought is that you are burning through media quickly (solely based on my own experience). I would get anywhere between 48 to 72 hours (2 or 3 days) using the BRS 10" media canister. I've since made a much bigger reactor and now can get a very consistent 8.24 to 8.28 variance between day/night over a couple weeks. The chart below is when my media is depleted and crashes fast. I have a pH alarm at 8.15 to warn me I need to change my media.

Water change containers sound like they are far away from a heavy CO2 area, which probably explains the higher pH but can see why that would be only a temporarily affect. CO2 absorption varies by setup and location but in my house you can see a very rapid decline in pH which I've been able to attribute entirely to CO2. For example, the chart below is my media getting close to end of life + an additional person in my house during that time period. Starts to increase as my guest left.

I haven't seen any benefit of running outside air into a CO2 media scrubber other than it may extend the media life slightly longer. I've dabbled with a CO2 re-circulating setup but find that the moisture accumulation causes a different set of problems that require additional equipment (such as solenoids) to manage.

There are options such as dosing Kalk, not via ATO but via a dosing pump to manage consistency and amounts, to me this can create a precipitate problem but is manageable if done correctly and slowly. If you are able to achieve a higher pH value already, changing your dosing regiment may cause different problems.

What ever you do, do it slowly my friend. If this hobby has taught me anything, it's patience. LOL!

For comparison sakes. I run my dKH around 9, Ca around 440 ppm and Mg around 1300 ppm. In order to achieve that I need to dose 215ml daily of Soda Ash and Cal. I dose about 40ml daily of Mg.

 

[DC Reefer]

Quick few questions... as I have experienced a similar problem and have been actively working solutions myself in a similar setup that you have described -- 2 part, fuge, CO2 scrubber

1. When your pH gets to 8.3 or it's highest point is that related to when you change out the CO2 media to fresh media? Or strictly just the water change?
2. How big is your water change? Any additives into the fresh saltwater?
3. When pH drops, is it dropping over hours (see screen shot below) or slowly over days?
4. How big is your CO2 media reactor? How often do you change the media?
5. Does your air intake go to your CO2 media reactor? Or are you feeding outside air separately into the tank?

My initial thought is that you are burning through media quickly (solely based on my own experience). I would get anywhere between 48 to 72 hours (2 or 3 days) using the BRS 10" media canister. I've since made a much bigger reactor and now can get a very consistent 8.24 to 8.28 variance between day/night over a couple weeks. The chart below is when my media is depleted and crashes fast. I have a pH alarm at 8.15 to warn me I need to change my media.

Water change containers sound like they are far away from a heavy CO2 area, which probably explains the higher pH but can see why that would be only a temporarily affect. CO2 absorption varies by setup and location but in my house you can see a very rapid decline in pH which I've been able to attribute entirely to CO2. For example, the chart below is my media getting close to end of life + an additional person in my house during that time period. Starts to increase as my guest left.

I haven't seen any benefit of running outside air into a CO2 media scrubber other than it may extend the media life slightly longer. I've dabbled with a CO2 re-circulating setup but find that the moisture accumulation causes a different set of problems that require additional equipment (such as solenoids) to manage.

There are options such as dosing Kalk, not via ATO but via a dosing pump to manage consistency and amounts, to me this can create a precipitate problem but is manageable if done correctly and slowly. If you are able to achieve a higher pH value already, changing your dosing regiment may cause different problems.

What ever you do, do it slowly my friend. If this hobby has taught me anything, it's patience. LOL!

For comparison sakes. I run my dKH around 9, Ca around 440 ppm and Mg around 1300 ppm. In order to achieve that I need to dose 215ml daily of Soda Ash and Cal. I dose about 40ml daily of Mg.

I run both of my CO2 scrubbers recirculating with my skimmers. One runs dry enough and the other runs wet. For the wet one i now having it run through an empty BRS dual media reactor with sponges prior to the co2 reactor. This has eliminated the excess moisture in my co2 reactor. I do collect a lot of excess Moisture in the 1st chamber of the dual reactor so I might be able to get my with a single reactor but only had an unused dual available.