Having troubles establishing pH

[Boog34]

I am wondering why my pH is low in comparison to what I have read/ heard is the ideal ranges?
My tank is still new, and I know patience is key. I am just trying to get an understanding of whats going on in my tank. Everything that I have read is the pH should be 8.0 to 8.5ish. During my initial cycle (fishless cycle), using the API Marine test kit I would be around 7.8. I did not test alkalinity at that time. After the cycle, ammonia steadily being converted to nitrate, I started worrying about pH, alkalinity, and calcium. Now I am measuring with a Hanna multi test kit. I started with pH at 7.7, alkalinity at 7.1dkh, and calcium at 438ppm.
I dosed soda ash to get to get alkalinity up to about 9.5 over the course of 3 days figuring pH would follow. It has stayed rock solid with alkalinity at 9.6.
I have done what I could to rule out CO2. I have a skimmer running 24/7, my return nozzles are just below the surface of the water breaking surface tension as well as 2 power heads. PH isn’t any different in the middle of the night or the middle of the day. I tried setting out a gallon of water inside and outside with an air stone for a bit longer than 12 hours and each were within 0.1 units of each other, the indoors one being the higher of the 2.
Is it something I should just let ride as long as thing are healthy in the tank? Or, is there something else that could be causing it that could lead to difficulties down the road that I can get a handle on now while the tank is still young?

Thanks!!!

 

[KrisReef]

What is your salinity at?

We were just discussing pH in another thread, and got pointed back to this one.

Reef Chemistry Question of the Day# 299: New Salt Water Parameters

Reef Chemistry Question of the Day 299 You are making a batch of new salt water for a water change, and realize that you overshot your salinity target. You measure the parameters to be: salinity 36 ppt pH 8.0 Calcium 455 ppm Alkalinity 9 dKH Magnesium 1380 ppm ORP 255 mV You then add some...

www.reef2reef.com

 

[ChrisRD]

I would test with something else. Preferably a calibrated meter. The indoor/ outdoor test results seem odd unless you have a well aerated home. Usually in the northeast this time of year we have elevated indoor CO2 levels (unless you're opening windows or have fresh air mechanical ventilation).

 

[Boog34]

What is your salinity at?

We were just discussing pH in another thread, and got pointed back to this one.

Reef Chemistry Question of the Day# 299: New Salt Water Parameters

Reef Chemistry Question of the Day 299 You are making a batch of new salt water for a water change, and realize that you overshot your salinity target. You measure the parameters to be: salinity 36 ppt pH 8.0 Calcium 455 ppm Alkalinity 9 dKH Magnesium 1380 ppm ORP 255 mV You then add some...

www.reef2reef.com

Salinity is at 35ppt

 

[Boog34]

I would test with something else. Preferably a calibrated meter. The indoor/ outdoor test results seem odd unless you have a well aerated home. Usually in the northeast this time of year we have elevated indoor CO2 levels (unless you're opening windows or have fresh air mechanical ventilation).

Yeah I figured it would be high CO2 as well. When I did the indoor/outdoor test, I did it with 2 different test kits, one with an API color comparator kit that looked pretty much identical at the 7.8 color. The other was with a Hanna Marine master photometer. That one gave me a 7.8 for indoors and 7.7 for outdoors. Kinda a head scratcher for me.

 

[Kodski]

Yeah I figured it would be high CO2 as well. When I did the indoor/outdoor test, I did it with 2 different test kits, one with an API color comparator kit that looked pretty much identical at the 7.8 color. The other was with a Hanna Marine master photometer. That one gave me a 7.8 for indoors and 7.7 for outdoors. Kinda a head scratcher for me.

Could also be as simple of an answer that its just your area. People don't realize that pollutants from roads, factories, forest fires, ect. all affect PH inside and outside.

As for ideas to improve your PH, this might sound like a joke, but get some house plants. Just one or two near the tank would do wonders. Pothos and snake plants are both very easy to take care of but produce a ton of oxygen. They are both good for your home and your tank. Ever since we got out first Pothos plant I've never seen my PH drop below 8.3 even in the dead of winter. My tank drains into a sump in my basement pretty much in the same room as my furnace and I have it fairly well sealed up which neither helps any for my PH. I will note that the plants are also in an adjacent room with a somewhat open door way, so it doesn't need to be in the same room necessarily.

Another few ideas, since I also added a refugium and started using kalk on my tank, I rarely see a PH below 8.5 and peaks around 8.7. I've never tried nor felt the need to try using a C02 scrubber on my tank due to my consistent PH levels. As far as ALK levels, I keep my around 10-10.5 DKH.

 

[Randy Holmes-Farley]

I tried setting out a gallon of water inside and outside with an air stone for a bit longer than 12 hours and each were within 0.1 units of each other, the indoors one being the higher of the 2.

Did the values change? My normal aeration test is a cup. A gallon is much slower.

 

[ingchr1]

I'm not sure I'd be too concerned with that pH at this point. My tank ran for years (since startup) below 8 then about a year ago I changed out a couple of my LED strip lights. When I did that my alkalinity consumption went significantly up from ~0.6 dKH per day to ~1.4 dKH per day. What also happened from that change is that my pH now gets above 8 during the day, topping out at around 8.3. I dose soda ash. My alkalinity consumption is actually up to ~2.0 dKH/day today.

Here's a post on it:

I recently swapped out my LED bars (different manufacturer, more output, different spectrum) and saw a significant change in my parameters. I discussed it in the quoted post below. One thing I did not mention in that post, was that my pH also significantly increased from what it had ever been in the past. From peaking at ~8.0 to peaking at ~8.25 and above.

Here is the pH graph. I swapped the LED bars on 6. Jan. On 25. Jan I reduced my photo period from 16hrs to 12hrs. Note that the spikes are when I dose soda ash. I have an AIO so my pH probe is in the same chamber that I dose into.

Graph to illustrate the spikes from dosing.

 

[Boog34]

Did the values change? My normal aeration test is a cup. A gallon is much slower.

PH of the tank at the time was 7.7 and the outside air sample was the same. The inside went up 0.1 pH units at 7.8.

 

[Randy Holmes-Farley]

PH of the tank at the time was 7.7 and the outside air sample was the same. The inside went up 0.1 pH units at 7.8.

It must be inadequate aeration or pH test error.

 

[Boog34]

It must be inadequate aeration or pH test error.

I wish, I would be less confused if I felt one of those were the issue. I aerated both samples in 5 gallon pales filled to about a gallon. They were aerated with air pumps and air stones. Total time they were bubbling was 13-14 hours. I set them out to bubble before I left for work and analyzed when I got home. Analyzed the tank once got the 7.7. I didn’t analyze again because that is what I had been getting all the time. I analyzed the indoor sample got the 7.8, which made me initially think I just needed more aeration of my tank. When I analyzed the outdoor sample and got the 7.7. It confused me so I analyzed both again with the same results. Only time I have seen a decent up shot in pH was shortly after I had dosed soda ash to bring up alkalinity, and it reached 8.0. By the time I analyzed the next evening it was back to 7.7.

 

[Randy Holmes-Farley]

I wish, I would be less confused if I felt one of those were the issue. I aerated both samples in 5 gallon pales filled to about a gallon. They were aerated with air pumps and air stones. Total time they were bubbling was 13-14 hours. I set them out to bubble before I left for work and analyzed when I got home. Analyzed the tank once got the 7.7. I didn’t analyze again because that is what I had been getting all the time. I analyzed the indoor sample got the 7.8, which made me initially think I just needed more aeration of my tank. When I analyzed the outdoor sample and got the 7.7. It confused me so I analyzed both again with the same results. Only time I have seen a decent up shot in pH was shortly after I had dosed soda ash to bring up alkalinity, and it reached 8.0. By the time I analyzed the next evening it was back to 7.7.

I don’t think it can be anything else. Alk and CO2 mathematically determine the pH.