Can Only Get Effluent in Calcium Reactor to 14.4 dKh

[PeterC99]

So for ARM media 6.8 is too high a pH and won’t dissolve much, 6.4 is probably about right to start getting good dissolution of the media. So your pH swings in the reactor are too large, you need to keep the reactor closer to 6.4 and it will produce far more alkalinity and Ca. For a calcium reactor to be most efficient it needs to attain an internal equilibrium of CO2 injected, the volume of incoming tank water (flow rate) and the pH of the incoming water, then you will get consistent stable dKh levels in the effluent. So keeping the variables you control (CO2 and flow rate) constant is important to attain equilibrium within the system.

Which brings me to my next point that most “control” oriented aquarist overlook. Having your controller open and close the CO2 solenoid is actually counter productive to this. It’s far more efficient (and actually easier on you) if you keep the CO2 solenoid open and limit the injected CO2 to exactly what you need. This accomplishes several things. An equilibrium within the reactor is easily achieved and maintained (unless you make a change to the CO2 amount or flowrate), pH inside the reactor becomes nearly constant (small daily swing based on the pH swing in the tank from day to night). The reactor can never “run away” from you, (because the only variable that produces Alk or Calcium is CO2) and there’s no pH probe that can and will ”drift” between calibrations. The result is a highly stable alkalinity in the effluent and your tank dKH becomes stable.

I’ve operated my CaRx both ways, and the “old school” manual way is far easier and more efficient. The last 3 years of running my system this way I have only had to make a major adjustment when I change my bottle which is a 20# tank and it last almost a year. (I dissolve about 23-30 lbs of media in that time).

So you are suggesting find the option bubble rate, set it there permanently, and not use the solenoid to regulate CO2? I would turn the pH probe off and just monitor the output effluent?

 

[Rick.45cal]

So you are suggesting find the option bubble rate, set it there permanently, and not use the solenoid to regulate CO2? I would turn the pH probe off and just monitor the output effluent?

Yes, finding the optimal bubble rate is the best solution, in my opinion. I’d open the solenoid and adjust the pH manually until it is stable somewhere around 6.4 according to your pH probe and then let it run for 24 hours and test your tank dKH again (you can also check the effluent dKH). Keep checking the tank dKH every 24 hours if it still declining increase the CO2 bubble rate, wait 24 hours then test again. I suggest testing alkalinity shortly before or after lights out as that tend to be the daily low, but if you are doing this it’s most important to check at the same time every day to make sure you’re not observing a daily swing. If it’s stable don’t make any adjustments and continue to monitor the tank dKh daily until you’re confident. Calcium reactors will make very gradual changes to a system so seeing which direction your alk is headed might take several days, or a week to notice a significant difference. In my experience it‘s best NOT to make lots of tiny adjustments, especially of multiple variables at once. So make a single adjustment if you have to and leave it alone for several days to see what effect the change you’ve made has. This all sounds much harder than it actually is to do .
(You don’t have to turn the pH probe off you can still use it to monitor the internal pH and use it as a guide to making any changes.)

 

[PeterC99]

Thank you Rick for the detailed explanation!

Part of my issue is that this calcium reactor is replacing 2 part, which I was dosing 110ml/day and getting precipitation in the aquarium killing a couple of corals. After installing the calcium reactor, Lost a torch because of an Alk swing (calcium reactor not replacing Alk as quickly as 2 part).

 

[Pwnm30rdi3]

When first ramping up my calcium reactor, I needed to manually substitute until I got things happy. I think the key is making adjustments and giving the reactor time to stabilize.

Personally I’m a huge advocate for the “old school” tuning method. Don’t bother with chasing PH.

 

[PeterC99]

When first ramping up my calcium reactor, I needed to manually substitute until I got things happy. I think the key is making adjustments and giving the reactor time to stabilize.

Personally I’m a huge advocate for the “old school” tuning method. Don’t bother with chasing PH.

Appreciate the advice of giving the reactor time to stabilize. Not sure why I thought I could switch from 2 part to calcium reactor without some adjustment period.

 

[FMF0331]

Any suggestions where to get Reborn media?

Also See Reborn on certain supply sites but looks like ARM stuff.

I just checked on marine depot website @ 11:10 pm, they have 8.8 lbs of reborn media in stock

 

[PeterC99]

I just checked on marine depot website @ 11:10 pm, they have 8.8 lbs of reborn media in stock

Thank you I’m going to order some today?

Isn’t this the same stuff in the Carib Sea?

Aragonite?​

 

[lakai]

CO2 looking a little low?

 

[PeterC99]

CO2 looking a little low?

10 lb tank. Just filled it 1 month ago.

 

[Pwnm30rdi3]

10 lb tank. Just filled it 1 month ago.

Looks normal to me!
CO2 tanks can only be reliably measured by weight. Mine sits around 800 PSI too.

I do run 12-15 PSI on the low side for more stable CO2 delivery. Anything under 5 or 6 PSI gets goofy with a lot of check valves in my experience.

 

[Deep]

Thank you I’m going to order some today?

Isn’t this the same stuff in the Carib Sea?

Aragonite?​

I havent seen your apex code, but it is probably because your PH swings are huge,
Your solenoid switches on below 6.4 ? and switches off at below 6.8 ? So what happens after it switches off at 6.4 ? the solenoid remains off till you reach 6.8 ?
if thats the case, then thats whats causing your low dkh in the effluent- you need to be around the melting PH of your Media all the time. So if you want to stay in the 6.4 range, then your solenoid should connect at 6.49 and disconnect at 6.40

 

[Crustaceon]

I had to push ARM a lot harder than reborn to get decent alk output. I think I was running 6.4 on 6.0 off.

 

[Rick.45cal]

So I used to run Reborn and this time over I switch to the ARM extra coarse and in my case it didn’t take much more CO2 to get the same output as Reborn. So I guess everyone’s mileage may vary.

I’d personally try running the reactor around 6.4 before I decided to swap medias.

(FWIW I actually really like the ARM media, and I was a diehard reborn fan)

 

[AquamanE]

Neptune has 2 pH solutions 7 and 10 ph. No other options.

Many other companies have calibration solution of 4.

 

[MabuyaQ]

There is too much media in your reactor, media needs enough contact time in CO2 enriched water to dissolve and CO2 needs enough contact time in water to dissolve. If you don't provide enough watervolume for either to dissolve you will run at low efficiency. Preferably 1/3 or less of reactorvolume as media is what you should aim for in a CARX.

 

[PeterC99]

There is too much media in your reactor, media needs enough contact time in CO2 enriched water to dissolve and CO2 needs enough contact time in water to dissolve. If you don't provide enough watervolume for either to dissolve you will run at low efficiency. Preferably 1/3 or less of reactorvolume as media is what you should aim for in a CARX.

Should I turn down my CARX pump? Would a slower pump give more contact time with the media?

 

[PeterC99]

I havent seen your apex code, but it is probably because your PH swings are huge,
Your solenoid switches on below 6.4 ? and switches off at below 6.8 ? So what happens after it switches off at 6.4 ? the solenoid remains off till you reach 6.8 ?
if thats the case, then thats whats causing your low dkh in the effluent- you need to be around the melting PH of your Media all the time. So if you want to stay in the 6.4 range, then your solenoid should connect at 6.49 and disconnect at 6.40

Thanks for the info on the small pH range. Watched the CARX installation videos and they suggested setting the wide pH on/off. Have narrowed the solenoid on/off to .2 and will monitor for further reductions.
Thank you!

 

[MabuyaQ]

Should I turn down my CARX pump? Would a slower pump give more contact time with the media?

Don't know which pump you mean, but if it is the circulation pump then no. It is basically 'extending' contact time. If you mean dosing pump, possibly. You want to aim for a contact time between 3.5 and 5 hours (see image below, tijd = time in hours, which shows Ca levels in ppm over time disolved at pH 6.5). To get volume, fill reactor with medium and water, drain the water and measure to get watervolume, divide by 3.5 and 5 to get optimal range of flowthrough. Less medium is more water is more flowthrough.

 

[jda]

Way late to the party, but did you get this figured out?

First, with just one droplet of liquid co2, the tank will read about 800 PSI. The PSI will not drop until there is nothing but gas in the tank... or near empty. Pick it up and swirl it or feel the weight to see how much is left.

Second, there is a link in my signature on how to tune a reactor by hand. This is the only way to go. Using a pH probe and controller is a waste of my time and I only recommend that people use it to monitor but never stop or impede the reactor from running. The pH probe is the weakest link in a system of otherwise usually good stuff. Let the reactor work 24/7. Get the output dKh to about 25, or so - not important if you are close. Then measure your output in ML and bubbles. This is your ratio to raise or lower in this same ratio to meet your tank demand. This will work until your media gets to like 20% and then when your tank dKh start to drop, then it is time to change media. If your corals (and mostly coralline which is a huge hog of carbonate and calcium) are growing, then you will need to up your reactor output a few times a year, but always in that same ratio. I ramble a lot, but the link has most of this in more detail.

 

[PeterC99]

Way late to the party, but did you get this figured out?

First, with just one droplet of liquid co2, the tank will read about 800 PSI. The PSI will not drop until there is nothing but gas in the tank... or near empty. Pick it up and swirl it or feel the weight to see how much is left.

Second, there is a link in my signature on how to tune a reactor by hand. This is the only way to go. Using a pH probe and controller is a waste of my time and I only recommend that people use it to monitor but never stop or impede the reactor from running. The pH probe is the weakest link in a system of otherwise usually good stuff. Let the reactor work 24/7. Get the output dKh to about 25, or so - not important if you are close. Then measure your output in ML and bubbles. This is your ratio to raise or lower in this same ratio to meet your tank demand. This will work until your media gets to like 20% and then when your tank dKh start to drop, then it is time to change media. If your corals (and mostly coralline which is a huge hog of carbonate and calcium) are growing, then you will need to up your reactor output a few times a year, but always in that same ratio. I ramble a lot, but the link has most of this in more detail.

Never too late to the party!!!

Did read your link to tune the reactor. Thanks! Have dialed in the calcium reactor to give Alk about 8.5. Next trying to get pH back up to 8.4.