Calcium Reactors and Depressed pH

[Reefahholic]

So...I know I'm the only reefer who struggles with low pH at night with my Calcium Reactor! I guess I need to bump up my Kalk dose.

What I really wanted to discuss is what are the best ways to combat the low pH of a Calcium Reactor and how low of a pH would kill corals. Last night my pH was down to 7.55 and this was on two freshly calibrated lab grade double junction probes and probably the lowest I've ever seen it in any tank I've setup. Needless to say it got me wondering about it. I have two different pH monitors on my Display (Apex and Milwaukee). I have had Pin-Point in the past and do not feel it's as accurate as the Milwaukee. The Pin-Point drifted like crazy. The Milwaukee calibrates so easily and always seems to be on point when I check it.

I know a lot of people don't test pH and feel it's useless, but I test it and think it's just another parameter that helps you make better decisions and understand your tank.

Like mentioned above, I will raise my Kalk dose and my CO2 scrubber went back online last night and it helps a lot (confirmed by Apex graph), but the media is expensive and I don't run it 24/7.

So to recap the questions:

1. What is the lowest pH you've seen or lowest pH corals will tolerate before you kill them? (Specifically Acropora).
2. What are the best ways to combat low pH and how do you make sure all the CO2 is utilized as efficiently as possible before it leaves the reactor chamber?
3. What's your Kalk dose hitting the water? (If you're not dripping 24/7 or running in a topoff reservoir.) I know you shouldn't raise pH more than 0.2 at any given time.

@OrionN uses a DIY modification that might help with this a little. I might try this later to see if it helps.

 

[OrionN]

I never worry about tank pH. I just your pH meter yesterday, and measure my tank pH and it was 8.4 in the middle of the day. Never measure my tank pH before.

 

[Reefahholic]

I never worry about tank pH. I just your pH meter yesterday, and measure my tank pH and it was 8.4 in the middle of the day. Never measure my tank pH before.

So if was 8.4 at 2-4pm...you're probably hitting 8.1-8.0 at night. That's good for a 20 year old tank. ;Hilarious

 

[SeaDweller]

Bruh... I think you’re more Type A Or neurotic than the rest of us, and I’m pretty Type A. Lol

my ph doesn’t peak past 8.1 and dips to maybe 7.8-7.9. combat it with a scrubber or fuge.

 

[pdxmonkeyboy]

There are a couple of things you can do:
1. Put the outlet of your calrx next to the inlet of your skimmer.
2. Open a window in your house
3. Run a BIG alage fuge at night
4. Dont worry about it, its fine.

 

[Pdash]

So...I know I'm the only reefer who struggles with low pH at night with my Calcium Reactor! I guess I need to bump up my Kalk dose.

What I really wanted to discuss is what are the best ways to combat the low pH of a Calcium Reactor and how low of a pH would kill corals. Last night my pH was down to 7.55 and this was on two freshly calibrated lab grade double junction probes and probably the lowest I've ever seen it in any tank I've setup. Needless to say it got me wondering about it. I have two different pH monitors on my Display (Apex and Milwaukee). I have had Pin-Point in the past and do not feel it's as accurate as the Milwaukee. The Pin-Point drifted like crazy. The Milwaukee calibrates so easily and always seems to be on point when I check it.

I know a lot of people don't test pH and feel it's useless, but I test it and think it's just another parameter that helps you make better decisions and understand your tank.

Like mentioned above, I will raise my Kalk dose and my CO2 scrubber went back online last night and it helps a lot (confirmed by Apex graph), but the media is expensive and I don't run it 24/7.

So to recap the questions:

1. What is the lowest pH you've seen or lowest pH corals will tolerate before you kill them? (Specifically Acropora).
2. What are the best ways to combat low pH and how do you make sure all the CO2 is utilized as efficiently as possible before it leaves the reactor chamber?
3. What's your Kalk dose hitting the water? (If you're not dripping 24/7 or running in a topoff reservoir.) I know you shouldn't raise pH more than 0.2 at any given time.

@OrionN uses a DIY modification that might help with this a little. I might try this later to see if it helps.

I'm no expert on calcium reactors, but if I set one up and was running 7.5 at night I'd suspect I have the reactor's co2 input tuned inefficiently.

 

[Reefahholic]

I'm no expert on calcium reactors, but if I set one up and was running 7.5 at night I'd suspect I have the reactor's co2 input tuned inefficiently.

I can see all the graphs on the Apex. CO2 is not tuned inefficiently. It's right on target. My Apex hasn't had to shut it on/off all night. I've literally been running at 6.88 for the last 12 hours with a .01 fluctuation earlier in the night.

It's strange because the other night my pH got down to 7.55. I put my scrubber on for the 2nd night and it keep it a lot higher. Scrubbers really help to combat the pH swing at night. No doubt about it. It only dropped to 7.84 when the scrubber was on. Tonight... I took the scrubber off before I left for work just to see how far the pH would drop again (curiosity got me) and looking at it now it's 7.82 (w/o the scrubber 5am). I wonder if the scrubber has a lag effect?

My high today was 8.11. Yesterday I don't think it even hit 8.0.

Maybe the bubbles affected the pH in the tank. It seems like each day there's less bubbles. I ran it for 24 hrs before injecting CO2. Maybe I should have ran 48 hrs.

Either way...it seems to be getting better and more stable. I'm liking it. pH is my only complaint so far.

 

[Reefahholic]

There are a couple of things you can do:
1. Put the outlet of your calrx next to the inlet of your skimmer.
2. Open a window in your house
3. Run a BIG alage fuge at night
4. Dont worry about it, its fine.

Then just take it offline in the morning??

 

[LC8Sumi]

Could be that the reactor is too big for your tank. In which case the only two solutions are:

1, drip the efluent oldschool (no steady stream type)
2, run the co2 only when the DT lights are on
+1, use a media (artifical) that disolves at a higher pH - this isn’t really an optimal approach, as said media don’t have the trace elements crushed coral have

 

[Reefahholic]

I never worry about tank pH. I just your pH meter yesterday, and measure my tank pH and it was 8.4 in the middle of the day. Never measure my tank pH before.

That's why your Gigantea always fluffy and shaggy.

 

[Reefahholic]

Could be that the reactor is too big for your tank. In which case the only two solutions are:

1, drip the efluent oldschool (no steady stream type)
2, run the co2 only when the DT lights are on

618 on a 75/G with extra chamber.

 

[LC8Sumi]

618 on a 75/G with extra chamber.

That sounds way too big in my opinion. For the constant stream method, that is.

 

[LC8Sumi]

If I read correctly it takes 12lbs of media. I had a reactor on my 65g that took 5lbs, and even that was borderline being too big for the constant stream method.

 

[LC8Sumi]

Or if you are commited to the constant stream method, you could try and take out 1/2-2/3 of the media, reduce the co2 accordingly & see if that helps

 

[Reefahholic]

That sounds way too big in my opinion. For the constant stream method, that is.

I was under the impression that bigger was better with reactors. There's been several people start smaller and when the colonies got large they were under gunned.

 

[Reefahholic]

Or if you are commited to the constant stream method, you could try and take out 1/2-2/3 of the media, reduce the co2 accordingly & see if that helps

I would just keep my scrubber on 24/7 if it came down to that. Or run a refugium and drip the effluent into the macro's.

 

[LC8Sumi]

I would just keep my scrubber on 24/7 if it came down to that. Or run a refugium and drip the effluent into the macro's.

You can ofcourse try and export excess co2 from the system, but it’s a lot easier not to put it in there in the first place. IMO.

 

[SneakyTortuga]

I was under the impression that bigger was better with reactors. There's been several people start smaller and when the colonies got large they were under gunned.

I don’t believe reducing the amount of media will help at all (but I may be wrong). Bigger just means you have to change the media less frequently.

I don’t know if you use the count drop rate method but Try the constant stream method. I use a similar size carx 2 stage set up with the constant method a 220 gallon. It allows you to run a higher ph in your reactor.

I used to dose kalk but got lazy. Just running a Fuge and a ph scrubber I keep my ph between 7.9-8.15

 

[LC8Sumi]

I don’t believe reducing the amount of media will help at all (but I may be wrong). Bigger just means you have to change the media less frequently.

I don’t know if you use the count drop rate method but Try the constant stream method. I use a similar size carx 2 stage set up with the constant method a 220 gallon. It allows you to run a higher ph in your reactor.

I used to dose kalk but got lazy. Just running a Fuge and a ph scrubber I keep my ph between 7.9-8.15

Bigger means more media. More media means bigger puffer-capacity, which means you need more co2 to decrease the pH in the reactor to get the same efluent potency. You don’t have to change the media that often in a bigger reactor as a result, but a bigger tank also puffers a bigger reactor (more co2 to get the same alk) better.
The 618 is rated for 300G, which is quite a bit more than 75G. If you leave in let’s say 1/3 of the media, you’ll need 1/3 of the co2 to get the same efluent potency, and as a result you’re pushing a lot less of the co2 and hydrogen ions into the tank.

 

[LC8Sumi]

Okay my previous one is confusing. What I’ve meant is that the bigger the reactor (and the more media you have), you need more co2 to get to the point when the media disolves. This in turn gives a more potent efluent (ca & alk). If you are able to get the target alkalinity in the tank before raising the pH in the reactor too high (high enough to stop the media disolving), then you’re good.