Raising PH with Limewater

[Huskymaniac]

@Randy Holmes-Farley what would cause PH values to not change when dosing fully saturated kalk via a doser over a 24 hour period. Trying to solve a low night PH issue as its been going down into the 7.6 range and even hit 7.58 the other day. Am I better off dripping it at night instead? Right now at I am using a cal reactor which I think is the reason for the low PH. Cal is 500 and alk is 8.8DKH and PH is 8 at peak and 7.6ish at low.

 

[Cory]

@Randy Holmes-Farley what would cause PH values to not change when dosing fully saturated kalk via a doser over a 24 hour period. Trying to solve a low night PH issue as its been going down into the 7.6 range and even hit 7.58 the other day. Am I better off dripping it at night instead? Right now at I am using a cal reactor which I think is the reason for the low PH. Cal is 500 and alk is 8.8DKH and PH is 8 at peak and 7.6ish at low.

Hpw much are you dosing in that time? Dripping wont greatly effect ph. Keep in mind thats raising alkalinity.

 

[Huskymaniac]

Hpw much are you dosing in that time? Dripping wont greatly effect ph. Keep in mind thats raising alkalinity.

Watching it on my trident. The alk/cal increase has been negligible. The apex takes 1.5 gallons and splits the dose every 15 minutes over 1 day period.

 

[Cory]

Watching it on my trident. The alk/cal increase has been negligible. The apex takes 1.5 gallons and splits the dose every 15 minutes over 1 day period.

What size system volume? Is the limewater fully saturated? Is the dosing container covered?

 

[Huskymaniac]

What size system volume? Is the limewater fully saturated? Is the dosing container covered?

Have about 125 gallons of water and the kalk is fully saturated 2 tsps per gallon. Its in a 5 gallon bucket with the lid on top.

 

[Huskymaniac]

Last night I changed dosing to deliver 24 hours of volume to a night time dosing and the PH was 7.68 so it's still not working. Help. I know buffers are not good but should I use one here to see if it works?

 

[Randy Holmes-Farley]

Buffers are, at best, half as effective as hydroxide (such as limewater/kalkwasser or a DIY two part using sodium hydroxide) per unit of alkalinity added. Many buffers will be far worse than that since they are not pure carbonate but also include bicarbonate, which lowers pH a tad.

There is no chance the hydroxide you are adding is "not working" on a molecular level but the degree of the observed effect depends on both the amount added and how fast you are aerating the water, driving back in high CO2 air.

You can readily see the effect if you add a bunch at once. When you spread it out, the apparent effect gets much smaller despite the actual CO2 consuming effect being the same, because the tank keeps pulling in high CO2 air, constantly offsetting the pH raising effect of the limewater.

 

[Huskymaniac]

Buffers are, at best, half as effective as hydroxide (such as limewater/kalkwasser or a DIY two part using sodium hydroxide) per unit of alkalinity added. Many buffers will be far worse than that since they are not pure carbonate but also include bicarbonate, which lowers pH a tad.

There is no chance the hydroxide you are adding is "not working" on a molecular level but the degree of the observed effect depends on both the amount added and how fast you are aerating the water, driving back in high CO2 air.

You can readily see the effect if you add a bunch at once. When you spread it out, the apparent effect gets much smaller despite the actual CO2 consuming effect being the same, because the tank keeps pulling in high CO2 air, constantly offsetting the pH raising effect of the limewater.

@Randy Holmes-Farley Am I better off doing larger doses then with a shorter interval or will I just end up back at the same place. Just trying to find the best solution.

 

[Huskymaniac]

@Randy Holmes-Farley the other option I was thinking was to setup my apex to dose the limewater if the PH just dropped below 7.7 as fall safe. My only concern is I would have no idea how much it would take to do it and would it be possible for it to add too much water over a period of time increasing calcium to much and even possibly overflowing the sump.

 

[Cory]

Probably get a co2 scrubber. Its a safer option than haphazardly dosing limewater. Imo lime shouldnt be used for increasing ph, but to maintain alkalinity.

 

[Randy Holmes-Farley]

@Randy Holmes-Farley the other option I was thinking was to setup my apex to dose the limewater if the PH just dropped below 7.7 as fall safe. My only concern is I would have no idea how much it would take to do it and would it be possible for it to add too much water over a period of time increasing calcium to much and even possibly overflowing the sump.

Yes, I do not recommend this option due to a variety of problems that might arise from overdosing (such as high alk, pH mismeasurement --> high pH, etc.).

 

[Huskymaniac]

Probably get a co2 scrubber. Its a safer option than haphazardly dosing limewater. Imo lime shouldnt be used for increasing ph, but to maintain alkalinity.

I used a scrubber before with marginal results. I think it may be attributed to my skimmer being smaller and putting out a rating 750 l/h. Some of the newer DC skimmers have ratings that are double. Would a bigger skimmer with a co2 scrubber put out better results? I also noticed that my my scrubber media dries out in 24 hours. 1 TSP of water added to the unit does very little. I am not really interested in drilling through my skimmer cup to recirc it. Not sure what your thoughts are on this?

 

[Cory]

I used a scrubber before with marginal results. I think it may be attributed to my skimmer being smaller and putting out a rating 750 l/h. Some of the newer DC skimmers have ratings that are double. Would a bigger skimmer with a co2 scrubber put out better results? I also noticed that my my scrubber media dries out in 24 hours. 1 TSP of water added to the unit does very little. I am not really interested in drilling through my skimmer cup to recirc it. Not sure what your thoughts are on this?

In this case what i would try is put a glass lid on your tank, and try to pump fresh outside air into the surface. Also feed the skimmer the same air. This might work. But you may need to do the same for the sump somehow.

 

[Huskymaniac]

In this case what i would try is put a glass lid on your tank, and try to pump fresh outside air into the surface. Also feed the skimmer the same air. This might work. But you may need to do the same for the sump somehow.

Its impossible for me to get a line outside or use glass tops on my tank. Do you think a larger skimmer will work?

 

[Cory]

Its impossible for me to get a line outside or use glass tops on my tank. Do you think a larger skimmer will work?

It might work but youll just exahst more co2 scrubbing media faster because your home has high indoor co2. But in theory yes a skimmer that pulls more air will produce quicker results. What skimmer are you using now? Why cant you run an air hose outside?

 

[Miller535]

Its impossible for me to get a line outside or use glass tops on my tank. Do you think a larger skimmer will work?

Personally I do not think a larger skimmer will work if your issue is too much co2 in a room. You're just going to input that high co2 faster into the tank. It'll likely give the same exact results because its putting the same exact air/co2 in faster

 

[Huskymaniac]

Personally I do not think a larger skimmer will work if your issue is too much co2 in a room. You're just going to input that high co2 faster into the tank. It'll likely give the same exact results because its putting the same exact air/co2 in faster

I don't think the issue is co2 in the room. I think the problem is co2 from the cal reactor. Theoretically a larger skimmer would push more 02 into the tank and if paired with a scrubber should boost that even more. Atleast I think.

 

[Huskymaniac]

It might work but youll just exahst more co2 scrubbing media faster because your home has high indoor co2. But in theory yes a skimmer that pulls more air will produce quicker results. What skimmer are you using now? Why cant you run an air hose outside?

J am using an aquamaxx cone 2 skimmer. My tank is in the basement and the the wall its on as adjacent to the crawl space. To get to the nearest outside wall I would have to go 60 feet across to the other side of the basement and the go up and rip through sheet rock, etc. Absolute nightmare and I am pretty confident internal co2 is not the issue as I keep the basement windows open 24/7. It has tk be related to the calcium reactor.

 

[Cory]

J am using an aquamaxx cone 2 skimmer. My tank is in the basement and the the wall its on as adjacent to the crawl space. To get to the nearest outside wall I would have to go 60 feet across to the other side of the basement and the go up and rip through sheet rock, etc. Absolute nightmare and I am pretty confident internal co2 is not the issue as I keep the basement windows open 24/7. It has tk be related to the calcium reactor.

Okay. Ever considered not using calcium reactor? I think you could use something else like 2 part. Glennf here doesnt use that and his tank is great packed with sps. That said, if co2 is high in your tank a bigger skimmer or another skimmer may help gas exchange.

 

[Huskymaniac]

Okay. Ever considered not using calcium reactor? I think you could use something else like 2 part. Glennf here doesnt use that and his tank is great packed with sps. That said, if co2 is high in your tank a bigger skimmer or another skimmer may help gas exchange.

My tank needs about 400ml's daily to keep parameters. It was just beyond reasonable to keep with that amount both for my sanity of having to make it and dollar wise.