So I was setting up my calcium reactor last night...
I went to calibrate the probe on my pH meter and its way off.
7 solution gave a reading of 6.7
10 solution gave a reading of 4.5

Yikes!

Not my fault though, I bought it used from a member of the local club.
:rolleyes:

Calcium reactor will wait another day!

fwiw, I went with the Coralife reactor rated at 500 gallons.

Calcium media is CaribSea aragonite for calcium reactors.

Milwaukee SMS122 pH monitor / controller

Probe was a PinPoint (going in the trash as it was probably allowed to dry out before I got it)

Milwaukee CO2 regulator - solenoid valve

Milwaukee bubble counter

Needle valve

20lb tank

Calibration fluid used was the Milwaukee brand for 10.01 and Milwaukee for 7.01

Ever thought about setting it by the KH in your tank ?

Are you using the fine or coarse media? I have found that I get a much greater disolve rate out of the course. Just food for thought

I'm not using that Coralife calcium reactor anymore, I now use a Geo 624.
I use the Carib Sea coarse ARM and yep, I set the drip rate based on the KH demand of the tank.

Thats how I did mine as well . No probe needed

Did you try to calibrate the probe. I sometimes find my "as-found" readings a bit off. I adjust the display by turning the trim-pot screw until it reads 7.00 or 10.00 (or 4.00 for my CO2 reactor). I go back and forth between the two buffers for the range I'm using. I consider the probe adequate if the pH reading stablizes withing 30 seconds and if I can get the reading to match the buffers after going back and forth, calibrating each time, less than 4 times.

If that does not work, then I do a mild acid soak in vinegar and HCl (pH ~ 1.5) for about 24 hrs, rinse with water and attempt to recalibrate.

I like the SMS121 on my DIY CO2 reactor. I find that it is hard to keep the drip rate constant because debris, or something, keeps interferring with the flow. The meter/controller ensures that the CO2 is added to maintain a constant pH. All I have to do is occasionally adjust the flow.

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My system: 135g display tank with live rock, 2-inch sand bed, 3x250w MH & 4x36" actinic 03 NO-flur lighting, DIY skimmer, DIY CO2 reactor, DIY Ca(OH)2 reactor (Neilson derivative). Sharing the same water are two 25 gallon tubs that are used as frag tanks.

Yes, I tried... the best I could get it was those readings.
The probe was garbage.. it had been purchased from a local club member in a complete CO2 setup.

With your setup that's getting clogged, could you install a sponge so the drip line wont clog? I'm curious how you built yours.
I run the Geo 624 now - Calcium Reactor 624

I built mine following Sanjay Joshi's design you can check out the specifications using this link:

Aquarium Frontiers On-Line: Feature

The design uses an up flow through the bed and water exits from the top of the reactor. I made some modifications to the design by installing block valves (1/4 turn ball valves) on either side of the pH probe. I use the valve upstream of the pH probe to cut back the recirculation flow so that the bed does not kick up too many particulates.

I'm attaching a short video clip of my design.

Aquarium Gallery - My DIY calcium reactor

To answer your other question, it does not seem to matter if I install a sponge prefilter. So, I think it is a thin slime layer that is growing on the 13-turn mini-globe valve that I use to regulate the flow into the reactor (just upstream of the recirculation pump). In order to maintain very low flow into the reactor, the feedvalve is very much closed. All I have to do is tweek it every few days (open it a little more). If I forget, the pH probe and controller ensure that too much CO2 is not added. The pH inside of the reactor is maintained at 6.5 to 6.7 pH.

- - sjg

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My system: 135g display tank with live rock, 2-inch sand bed, 3x250w MH & 4x36" actinic 03 NO-flur lighting, DIY skimmer, DIY CO2 reactor, DIY Ca(OH)2 reactor (Neilson derivative). Sharing the same water are two 25 gallon tubs that are used as frag tanks.