I need to Revisit PH Again

[AKL1950]

My tank is a little over a year old now and very stable except for one thing. PH. Through a year of observation, I’m pretty sure the issue revolves around the CO2 level in the house. It’s a new house and very well sealed. Here’s the parameters.

Tank plus sump is about 180 gallons.
Temp 78-80, Salinity 35.0, Alk 8.0-8.1, Ca 440, Mag 1470, NO3 15, PO4 0.08-0.11.
Tank is bare bottom and I use IO Reef Crystals. I dose 20 ml Alk and 5 ml of Ca daily. Water changes are 2 gallons/day with an Auto change system.

I try to keep my PH around 8.1-8.2, but it keeps dropping to 7.5-7.6. I run a scrubber and with new media I can get it up to 8.1-8.2, but within 4-5 days it starts dropping again.

The problem. When it’s cooler outside, I can open the doors and windows. PH after a few hours will jump up to around 8.3. However, summer is upon us here in central Florida and night time temps are now close to 80 degrees. Opening the house up brings the hot air in and the tank temp starts rising to 81 well before I can get the PH to rise.

Is there a method is help raise PH chemically without causing a similar jump in Alkalinity? I’m considering using sodium carbonate. Is that a safe way to get a good rise in PH without affecting the other parameters very much?

 

[Batt]

If you us kalkwasser it will keep your ph stable. And I learned that ph will keep your corals healthy and it not proven but stop stn and rtn from my experience. My ph stay at 8.5 day and night 8.3.

 

[jda]

Whatever you decide, find a plan for exchanging massive amounts of house air when a cold spell comes through. Even 74 at night will work and the few extra dimes that you have to pay for AC will be cheaper than a co2 reactor, media, shipping and all of that. A completely aired out home will last usually a week or 10 days, for me at least, before the co2 get high enough to worry about (700+). I have to do this in reverse in the winter - I just wait for a day with highs in the 40s and then move a ton of air into my house.

A $40-50 co2 meter might be a good idea.

Kalk works great, but overdose can crash a tank. Be careful with it, but it is very effective. Kalk is more effective than sodium carbonate. co2 scrubber works too, but the media does not always last long. Outside air to the skimmer intake can work some too - not as good as airing out the home, but a help.

A reactor, media, etc. might be a hundy or two. A buck or two of extra AC a month is like 4 years before you pay off a new device for pH.

 

[prokhk]

Not a chemical solution, but you could get a chiller to control temperature which would let you open windows when its hot. You could also try a refugium that is on at night where the algae would hopefully photosynthesize some of the CO2. If there is a day/night cycle you can time your alk dosing for when pH goes down.

 

[jda]

Yes, ^. Reverse light cycle fuges do work as well as anything outside of Kalk and are quite safe.

 

[AKL1950]

If you us kalkwasser it will keep your ph stable. And I learned that ph will keep your corals healthy and it not proven but stop stn and rtn from my experience. My ph stay at 8.5 day and night 8.3.

Whatever you decide, find a plan for exchanging massive amounts of house air when a cold spell comes through. Even 74 at night will work and the few extra dimes that you have to pay for AC will be cheaper than a co2 reactor, media, shipping and all of that. A completely aired out home will last usually a week or 10 days, for me at least, before the co2 get high enough to worry about (700+). I have to do this in reverse in the winter - I just wait for a day with highs in the 40s and then move a ton of air into my house.

A $40-50 co2 meter might be a good idea.

Kalk works great, but overdose can crash a tank. Be careful with it, but it is very effective. Kalk is more effective than sodium carbonate. co2 scrubber works too, but the media does not always last long. Outside air to the skimmer intake can work some too - not as good as airing out the home, but a help.

A reactor, media, etc. might be a hundy or two. A buck or two of extra AC a month is like 4 years before you pay off a new device for pH.

I’ve been reluctant about going the kalkwasser route. Trying to avoid more equipment Trying to learn new chemistry.

@jda I like the idea of a house CO2 meter. That way I can see the relationship of house CO2 and tank PH. Would help giving me a better knowledge of when I need to air out the house Instead of reacting to the PH dropping. Right now I just wait for the thunderstorms to roll through so I can open the doors and let the storm cycle the air for me. I thought about not breathing so much, but that didn’t work out.

Thanks fro the advice.

 

[AKL1950]

Not a chemical solution, but you could get a chiller to control temperature which would let you open windows when its hot. You could also try a refugium that is on at night where the algae would hopefully photosynthesize some of the CO2. If there is a day/night cycle you can time your alk dosing for when pH goes down.

Interesting point I never thought about. My Apex crashed a few month back. When I reinstalled the new one, I set up the Alk dosing on a 24 hour schedule instead of a 5 hour window at night like it was before. That’s about the time I started seeing the bigger swings in PH. I wonder if there’s a correlation. Think I’ll go back to just dosing Alk at night and see if that helps.

 

[jda]

There are some decent co2 meters on amazon for $40-60. They have batteries, but they do not last, so you have to leave them plugged in. Just get one with a USB C or whatever it needs.

A box fan in one window, and an open window on the other side of the house, can move a lot of air in quickly. Whole house fan is best, but not worth the money unless you can use it for more than just this. A big-time air out will get me into the low 400s and it is a week, or more, until we get to 700 - pretty big house and just the three of us and a dog anymore... probably less time if everybody came home.

When you get a meter, anything under 700, or so, is not usually a problem for me. 425-500 is better, but not doable in the winter all of the time. Over 800 and tank pH will move and this is supposedly not good for humans either long term.

 

[AKL1950]

There are some decent co2 meters on amazon for $40-60. They have batteries, but they do not last, so you have to leave them plugged in. Just get one with a USB C or whatever it needs.

A box fan in one window, and an open window on the other side of the house, can move a lot of air in quickly. Whole house fan is best, but not worth the money unless you can use it for more than just this. A big-time air out will get me into the low 400s and it is a week, or more, until we get to 700 - pretty big house and just the three of us and a dog anymore... probably less time if everybody came home.

When you get a meter, anything under 700, or so, is not usually a problem for me. 425-500 is better, but not doable in the winter all of the time. Over 800 and tank pH will move and this is supposedly not good for humans either long term.

I like the idea. I will be very easy to put a box fan in front of the Lanai glass door and crack open the front door. Even if I only do it for an hour a day early in the morning or late at night, it should be sufficient. I like the simple solutions that don’t require messing with tank chemistry.

 

[Randy Holmes-Farley]

Is there a method is help raise PH chemically without causing a similar jump in Alkalinity? I’m considering using sodium carbonate. Is that a safe way to get a good rise in PH without affecting the other parameters very much

There is no chemical that can raise pH and not raise alkalinity, despite some uneducated claims by certain hobby suppliers.

Carbonate will raise pH and alk.

Hydroxide will raise pH twice as much as carbonate per unit of alk added.

Bicarbonate and most organic alk additives (formate, acetate) will not raise pH.

 

[AKL1950]

There is no chemical that can raise pH and not raise alkalinity, despite some uneducated claims by certain hobby suppliers.

Carbonate will raise pH and alk.

Hydroxide will raise pH twice as much as carbonate per unit of alk added.

Bicarbonate and most organic alk additives (formate, acetate) will not raise pH.

Thanks Randy. I really dislike the idea of putting chemicals in the tank and would much rather stick to the natural solution.

I got a CO2 meter for the house, and sure enough, the CO2 level in the area of the tank was running over 800. Made some easy changes to help move fresh air through the house and now it’s staying around 450-500. Since I’ve done that, Tank PH has been holding between 8.05 night and 8.2 Day. I love simple fixes. also didn’t realize this was such a cause, but I cook with gas. Just running a stove gas burner for 30 minutes and the C02 jumps 100-150 points in the kitchen. Guess I need to go out to eat more often.

 

[jda]

If your home airing-out is periodic, make sure that the air in the stand (if you have one) is exchanged too. I keep the doors open in the cold winter times since I bring in fresh air periodically want want it to get in there. My stand would sometimes be 200-300 ppm higher than the air in the room around the tank... but not always.

 

[BanZI29]

I am curious, what if you were to add an aerator pump, like they have in freshwater tanks? Would that help raise pH since it would add oxygen to the water?

 

[jda]

I am no chemist, but if you are mixing in higher co2 air, it will be status quo since it is pumping in that air. This assumes that your tank is aerated well enough already.

 

[Randy Holmes-Farley]

I am curious, what if you were to add an aerator pump, like they have in freshwater tanks? Would that help raise pH since it would add oxygen to the water?

pH is unrelated to oxygen.

Increasing aeration can raise or lower pH depending on the relative amount of CO2 in the tank relative to the air used for the aeration.