PH, The Fireplace, CO2 and Soda Lime....A Brief History

AmherstReef

New member
Historically my PH has always been low, in the 7.8-7.9 range, which was fine and I never worried about it. When I started dosing Kalk it bumped up to around 8.0-8.1 which again I was perfectly happy with.

This year got me very nervous though, with the cooler weather and the house closed up the PH dropped back to 7.8-7.9, but over the past month with the really cold weather my wife and daughter started using our ventless fireplace on a regular basis. It does a great job of heating up the house but raises the indoor CO2 tremendously, I watched my PH drop to very low levels, 7.7 to 7.6 to 7.5. The moment the fireplace went off the PH would slowly start climbing back but I knew I need to do something else.

The first thing I did was run an airline from my skimmer into the basement. That alone worked much better than I expected with the PH climbing to 8.1-8.2 and dropping only to about 7.8 when the fireplace was on for awhile.

During this time I had also placed an order for soda lime as another solution, it came yesterday and last night I fabricated a CO2 Scrubber out of a 16 oz water bottle. I filled it about half way and hooked it up to the airline in the basement. Well to my total shock this morning almost half of the soda lime I put in has already turned a light shade of purple, not sure how dark the purple gets? Obviously it is doing its job although I did not expect the soda lime to exhaust so quickly, maybe I need to use a larger container with more soda lime.

Anyways, that's my PH nightmare of sorts over the past 3-4 weeks, thanks for listening.


PS: Since I know everyone will ask, all my other parameters are fine.

Alk 10.3
Ca 470
Mg 1320
PO4 0.045
Salinity 1.026
Temp 78-79
 
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I'm curious: Were you seeing any detrimental effects in the aquarium when the pH was low? I'm asking because we can sometimes get into trouble "chasing numbers", when in reality, things are just fine.

How are you measuring pH? If it's a probe, how often are you calibrating it?
 
I have a probe and a handheld which I calibrate often and am confident with their readings.

My history clearly shows I am not chasing numbers, simply trying to counteract the seriously low readings caused by the fireplace. As Randy Farley-Holmes has said decalcification can begin once PH hits 7.7 or below. I would rather solve the low PH before I have an issue.
 
I'm assuming the ventless fireplace is gas? I've heard they're really not a great idea for the CO2 reason. Could you add a vent to the outside?
 
The fireplace is gas and been around for years, long before my reef tank. From what I have read a ventless fireplace cannot be vented.

As I mentioned in the original post the airline to the basement and subsequent addition of soda lime seems to have corrected the severe PH drop when the fireplace is used.
 
Obviously the room air is high an the soda lime is cleaning room air. Perhaps a smaller inlet to the scrubber would get more bang for the buck or running outside air through the scrubber might do it. Mine lasts anywhere form 3 to 5 weeks.
 
Obviously the room air is high an the soda lime is cleaning room air. Perhaps a smaller inlet to the scrubber would get more bang for the buck or running outside air through the scrubber might do it. Mine lasts anywhere form 3 to 5 weeks.

The hose from the skimmer to the scrubber is 3/8 inch just because that's what fit the skimmer intake. Maybe I put to many holes in the bottom. There's probably 30 or more.
 
Get rid of the fireplace? ;)

In all seriousness, you're going to really struggle with CO2 reduction with that much of it coming into the house from the fireplace. It's almost like running a car indoors... You're going to go through buckets of sodasorb to keep up with that amount of CO2 production. The exterior airline is your best bet
 
I would get rid of it but my wife and daughter would never let me LOL.

I get your point about the CO2 but it is obviously very different than CO.

I considered running the airline outside but running it to the basement made such a difference I may just stick with that and the soda lime until the weather breaks. Plus within a month or so i will be moving my sump into the basement which should help.
 
Wood stove!

Seriously though, with the indoor air high in CO2, it will always be a struggle. Sounds like you're doing pretty much all you can.
 
The hose from the skimmer to the scrubber is 3/8 inch just because that's what fit the skimmer intake. Maybe I put to many holes in the bottom. There's probably 30 or more.

You could just cover some with duct tape and see if that helps any.
 
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