Calcium Reactor Help

[Biglurr54]

So I set up my calcium reactor and I have been nervous about my tanks pH. My tank had been resting at 8.2pH when I was dosing 2 part. My fuge kept things stable at night. I am not running a skimmer and the sump is in a draft basement so I doubt that excess co2 is an issue. My tank is running at an alk of 10.5 and Im considering lowering it to 9.5


I set up my Geo 612 reactor using a masterflex pump and a custom dual stage CO2 regulator. I set the reactor to 6.55ph and have been dialing in my effluent speed to match the tanks demand. I placed the effluent discharge so it drips into the fuge. My ph went from 8.2 to 7.83-7.90. It is holding in this range.


I took a phosban 150 reactor that I had and filled it with media and had the effluent flow through it. I am not sure how effective the diy 2nd chamber is as I believe the effluent is flowing around the fittings in the phosban reactor. They are meant for higher flow. I am considering placing a fitting at the bottom of the reactor and getting rid of the tube in the middle.


A couple questions:

Should I be concerned about that tanks ph as it is?

Should the effluent flow from the top down through the media, out the bottom of the reactor, then into the sump. (This would prevent and CO2 bubble from ever making it to the tank)

Is there anything else I should change to help raise the tank ph a little?

 

[Biglurr54]

Pics

 

[spartanman22]

I’ve got a CO2 scrubber on my tank and still haven’t been able to get pH above 7.9. My tank runs between 7.6 and 7.9 according to my apex. Haven’t notice any issues with my tank. It’s been this way since setting it up 2 years ago. Things seem to be going well enough.

 

[LouieP]

I wouldnt worry about ph at all.

 

[Biglurr54]

I am going to lower my alk to 9.5 form 10.5. How long should I stretch that drop out.

 

[Biglurr54]

Also how long between adjustments to the reactor should I wait to see the changes in the tank. I'm currently doing 2 alk tests a day, and I'm making adjustments in the evening after the second test. Is that a good schedule?

 

[2una]

Your alk will go up & down like your ph does but in inverse.
Alk peak will likely be at lights on & then it will drop till lights go out then rise again during the lights off period.
So a check at around lights on will give you your alk high.
I've got a calcium reactor so my alk is stable is a load of bull.....my tank swings close to 1 dkh down then 1 dkh back up again every day.(i'm heavy stocked)

 

[TMB]

I would wait 48 hours between changes to your reactor. Maybe even longer if it's not way out of whack.
You could lower your Alk in 1 day if your wanted to, however it makes more sense to let it fall slowly over a week or so.
I'm assuming you're using a PH controller? If so, you could just raise the reactor PH some, to like 6.7 or so, and let the Alk drop nice and slow.
How much effluent are you dossing Mil/Min? Also, have you double checked your Reactor Probe? 6.5 seems pretty low.

 

[jda]

You are probably wasting co2, which is causing the tank pH to raise since it gets into the tank. A finely tuned reactor will not usually let the pH drop that far. This is pretty common in the on/off dumping paradigm of using a pH controller inside of the CaRx. I can show you how to tune a reactor by hand, but it takes work and is not for everybody, but it is steady and consistent and does not waste any co2 and the tank pH stays higher.

 

[Biglurr54]

I currently have a medium flow Metering valve. I am switching it out for a low flow metering valve (in the mail).

Right now I have to use my Apex to control the solenoid. It is set to keep the pH at 6.55 and it keeps it within .03.

I'm trying with the idea of raising the pH in the reactor at night.

 

[Biglurr54]

Jda I would love to learn how to tune by hand. I am always ready to learn. I just have to get a better metering valve so I can control the bubble count better.

 

[wangspeed]

How much effluent are you pumping out? On my 220 gallon, I have my Watson Marlow set to 20 ml/min

 

[Biglurr54]

Mine is an analog pump. So it's is 0 to 10. Its turned down to almost just a few drips a second.

 

[wangspeed]

Mine is an analog pump. So it's is 0 to 10. Its turned down to almost just a few drips a second.

Measure it for a few minutes with a graduated container. You really don’t want to pump too much through, or you waste CO2 and drop PH in the tank.

 

[jda]

Hollar when you get the better metering valve - it will help. Getting a constant tune will involve ignoring/removing the co2 controller, measuring effluent dKh, counting bubbles and measuring effluent in mls. It is kinda kind setting the timing on a car or getting the mixture right on a carburetor... once you "get it," then you can just glance at it and see if it is OK, or if it needs adjustment.

Does the GEO trap excess co2 in the reactor? This is easy to tell if the tube that pulls from the reactor (intake side of the pump) is below the top just a bit.

 

[Biglurr54]

The Geo is not supposed to collect gass. The union fitting they used looks about flush with the lid. There are a few small bubbles that it doesn't seem to suck up.

The metering valve comes in on sat. Hopefully it will be an easy swap without too many hardware store runs....

 

[jda]

It can help you tune if it will collect gas. Anything that it does not collect just goes into the tank and lowers the pH. That is too bad.

Just take the whole regulator and some wrenches to the hardware store with you. :)

 

[DCR]

Hollar when you get the better metering valve - it will help. Getting a constant tune will involve ignoring/removing the co2 controller, measuring effluent dKh, counting bubbles and measuring effluent in mls. It is kinda kind setting the timing on a car or getting the mixture right on a carburetor... once you "get it," then you can just glance at it and see if it is OK, or if it needs adjustment.

Does the GEO trap excess co2 in the reactor? This is easy to tell if the tube that pulls from the reactor (intake side of the pump) is below the top just a bit.

I have read your posts on tuning a reactor and they make a lot of sense to me. The Geo reactors are upflow through the reactor with the outlet at the top and will not really trap excess CO2 as you describe. Is it worth the trouble to re-plumb them to make them a down flow design to trap the excess CO2, or would it be better to just add a second stage?

 

[jda]

No, it is not necessary or probably worth modifying it. Korallin is reverse flow too and they have the intake to the pump stick down an inch or two into the body and not be flush with the top.

Second chamber only does anything if there is excess co2 leaving the first chamber. You can tune them so that there is no extra co2 and then a second chamber does not do anything.

 

[Biglurr54]

I can prop the reactor at a slight angle. That will trap excess gass.

The emtering valve I bought says it's 1/8 swagelok tube fittings but they looked 1/4 in the photos....

If it's 1/8 then I have what I need. If it's 1/4 I need a couple of fittings. Either way, should be straight forward.