PH !!??? I can’t seem to get and keep it above 8.0

JAWSIII · Mar 29, 2021

Hi all I have a 65 DT with a 15 sump that has been up and running for almost a year. Since the beginning I have struggled to keep the PH above 8.0. I run a skimmer since the beginning and back about 6 months ago I read an article regarding higher CO2 levels in the home so I ran tube from my skimmer intake Venturi directly outside. Within about 3 hrs my PH tested at 8.4 so I thought Viola ! That was it but I checked PH a few days later and it was back down to 7.8 with the fresh air line. So for the last 6 months or so it hovers between 7.8 and 8.0 my corals seem just ok but nothing has grown at all except my torch.

On this past Thursday I received a CO2 scrubber that I got from BRS and hooked it up on Thursday night using the BRS color changing CO2 media. When I checked the PH Friday 8.0, Saturday 8.0 , Sunday 7.8 and today 8.0.

I do top off with RO water and I checked the PH of that by itself and it was well below 7.5 ( to low for test kit to register). I usually add about 1/2 gallon every few days to my system.

should I be looking to something else?? Or is it just the RO water top off that keeps it low? My current (today) readings are...

Cal. 440
Mag 1440
KH 9.1
Salinity 1.025
PH 8.0
Temp 78
Phosphate.04
Trite 0
Amonia 0
Trate 10-15

Any ideas. ??

ZoWhat · Mar 29, 2021

Other things to consider:

Lighting - your highest pH reading should be occurring during the end of your brightest light cycle. Ive noticed if I choose to dim my lights for some good reason my pH will not peak out. I know pH is the power of hydrogen and more hydrogen is produced during photosynthesis. I don't know you lighting setup nor your light cycles, so check that.

Surface agitation - again back to the power of hydrogen, more waterline agitation will help release gases (co2) out of the DT increading pH

Do you run your furnace fan 24/7? The more humans and pets (dogs/cats) breathing in the house, the more co2 is being built up inside the house from breathing. Running your furnace fan 24/7 will help circulate the air exchange in your home. Unfortunately running a furnace fan 24/7 will add abot $30-$50 to your electric bill

Consider putting lots of house plants in sunny windows inside your home:

Mical · Mar 29, 2021

What are you measuring Ph with? If it's mechanical device has it been calibrated lately?

Dkmoo · Mar 29, 2021

For your scrubber do you run recirculating or open? Recirculating may help itna bit better

Also since you confirmed its a high co2 from room air. The rest of your DT surface is actually sucking co2 back into the system anywhere there is surface agitation. (Dt, overflow, sump). This will not be mitigated without decreasing the co2 of your room. Its warmer now. Open some windows.

If you have an autodoser and has decently high alk demand, you can switch from dosing bicarbonate daily to dosing soda ash daily. Split it multiple times a day to even out the pH boost.

Also get a fuge on oppo light cycles will help too

JAWSIII · Mar 29, 2021

zoa what said:
Other things to consider:

Lighting - your highest pH reading should be occurring during the end of your brightest light cycle. Ive noticed if I choose to dim my lights for some good reason my pH will not peak out. I know pH is the power of hydrogen and more hydrogen is produced during photosynthesis. I don't know you lighting setup nor your light cycles, so check that.

Surface agitation - again back to the power of hydrogen, more waterline agitation will help release gases (co2) out of the DT increading pH

Do you run your furnace fan 24/7? The more humans and pets (dogs/cats) breathing in the house, the more co2 is being built up inside the house from breathing. Running your furnace fan 24/7 will help circulate the air exchange in your home. Unfortunately running a furnace fan 24/7 will add abot $30-$50 to your electric bill

Lights are AI primes on this schedule

JAWSIII · Mar 29, 2021

Mical said:
What are you measuring Ph with? If it's mechanical device has it been calibrated lately?

I have only ever had the high range API vial test kit.

Mical · Mar 29, 2021

JAWSIII said:
I have only ever had the high range API vial test kit.

I'd find another test kit or device, API is on the lower end of testing.

JAWSIII · Mar 29, 2021

Dkmoo said:
For your scrubber do you run recirculating or open? Recirculating may help itna bit better

Also since you confirmed its a high co2 from room air. The rest of your DT surface is actually sucking co2 back into the system anywhere there is surface agitation. (Dt, overflow, sump). This will not be mitigated without decreasing the co2 of your room. Its warmer now. Open some windows.

If you have an autodoser and has decently high alk demand, you can switch from dosing bicarbonate daily to dosing soda ash daily. Split it multiple times a day to even out the pH boost.

Also get a fuge on oppo light cycles will help too

I can agitate the surface in my sump with an air stone. I don’t have a auto doser. I will try the air stone It’s getting to warm here to keep windows open unfortunately. I live in south louisana.

Dkmoo · Mar 29, 2021

JAWSIII said:
I can agitate the surface in my sump with an air stone. I don’t have a auto doser. I will try the air stone It’s getting to warm here to keep windows open unfortunately. I live in south louisana.

Agitation only helps if your tanks co2 concentration is higher than ambient room

I'm not sure thats your case. Since once you used outside air your pH increased. To me that means your ambient room is Higher co2 than your tank. My post is suggesting that the agitation from dt/overflow/sump is actually negating the effect of your co2 scrubber by putting more co2 back into your system. Adding additional air agitation will not help in this situation

Edit:especially if you will be closing your windows

JAWSIII · Mar 29, 2021

Dkmoo said:
Agitation only helps if your tanks co2 concentration is higher than ambient room

I'm not sure thats your case. Since once you used outside air your pH increased. To me that means your ambient room is Higher co2 than your tank. My post is suggesting that the agitation from dt/overflow/sump is actually negating the effect of your co2 scrubber by putting more co2 back into your system. Adding additional air agitation will not help in this situation

Edit:especially if you will be closing your windows

Ohhh. That makes sense. Thanks.

Snoopy 67 · Mar 29, 2021

PH is considered the "brat" of saltwater because it does what it wants & there is not much we can do to change it. Nothing wrong with 8.0

jmichaelh7 · Mar 29, 2021

Surface agitation, Open windows , ... co2 scrubber. I just started a refugium in the sump to maintain 8.14 dipping to 8 at night. Too early to tell, but maybe something for you to consider in the future ?

fachatga · Apr 22, 2021

Make sure to use a few different tests though. I’ve found wildly varying test results. It even sure which one I believe. I even have a few probes spending over $50 on one. So disappointed. The most expensive one swing from 8.1 to 5.5 one night in about 39 seconds. The probe now tells me I’m at 6.5. But some days it’s 7.6. And I’ve calibrated it a dozen times. Most tests I use vary from 7.8-7.9 to 8.2. So I’m not even sure what mine is. But anywhere in that range is okay. Always good to try for higher since you’ll have better growth. But I wouldn’t change too much more until you have some confirming tests.

WallyB · Apr 22, 2021

I tried the same. Both Airline and CO2 Scubber, and together. Kalk as well.

Each did improve PH on average.

CO2 Scrubber was just too expensive to run.

I still run airline to all my skimmers and it's better than not having an airline.

Since you don't have a probe is it possible you are measuring at the wrong time (ie different times).
You need test to accurately compare PH level changes, testing must be done at the same hour/minute.

PH does swing/cycle like other folks mention and PH Does go up/down in relation to when you lights are on or off.
That show up an a probe with Logging, not manual Test kits, unless you test a lot.

I also even tried a 3 way Valve that would only run the CO2 Scrubber during the Low PH cycle.

Like this setup I did, hoping to extend the CO2 Media, and Flatten the LOWs.

It helped a bit, but again, the Media didn't last long enough to justify the cost.

I even got a CO2 Monitor to see C02 Level in the Basement.

SImply opening the Basement Windows where my Tank and Sumps ares helped with PH, but not as much.

There is one way that you can Bring UP PH quite a bit. That's using kalkwasser.
Kalk does bring up PH and quickly, which can cause big problems.

It has it limitations and risks as well, and that's a topic in itself since it will also bring up your Alk and Calcium, and then you can't be dosing other additives.

I was going to try this (drip Kalk) during Low's just like Running CO2 Scurbber during low PH levels.

That got too complicated, so I didn't ever try it.

To summarize, when you dose Two Part like ESV, it wil bring up PH just like KALK.
Problem is you wont' get the benefits of higher PH till you have a large enough Coral Load and then you add enough Two Part distributed over the day to keep PH higher.

The opposite happens (Lowered PH) for folks who use CO2 Reactors.

Basically now that my SPS are consuming Alk/Calcium and I'm dosing more Two Part, along with Fresh AIr line (No CO2 Scrubber), I finally got my PH about as high as I'll ever get it. Corals started growing too.