Ca Reactor & Tank pH Probe Calibration

[cmhollis]

Prior to starting up my calcium reactor, my tank pH would stay in the 8.2 - 8.4 range, and I was happy with that. Now my CR has been up and running for 2 days, and according to my system pH probe (located in the fuge) my system pH is 8.6 - 8.8. Thinking "That can't be right" (since a calcium reactor should be depressing system pH), I calibrated both pH probes last night using the individual pH standard packets. After calibration, system pH was reading 7.98 (I expected it to read in this ballpark due to CR operation). So last night I added a tsp of kalk powder to the sump and stirred it in till everything was dissolved. Checked the tank pH about an hour later on the ACIII and it read 8.26 or so.

I thought that everything was good, and went to bed. This morning I got up, and pH was again down around 8.00, so I added another spoon of kalk. Throughout the day after adding this pH stayed in the 8.2 - 8.3 range. I figured everything was good again.

So I just checked the display on the ACIII, and it read 8.65 or so, but it is coming down.

Has anyone encountered something similar when starting up a CR? I did check to make sure nothing was fouling the probe, and that it is completely submerged.

I am thinking about shutting down the CR for a couple of days and see what effect that has on system pH.

Thanks,

Mike

 

[laverda]

Form my very limited knowledge, it sounds like you ALK is too low, allowing the PH to swing a lot. If your ALk is in the proper range your PH should not swing as much. PH will normally increase during the day and go down at night. That is why most people only run their CR when the lights are on and PH is higher and run kalk reactors and refugiums at night to raise the PH. I hope this helps. Please correct me if I am wrong as I am going to be hooking up my CR shortly.

 

[cmhollis]

Laverda,

I tested my Caclium and alk yesterday. Calcium was 410, alk was 8.45.

Those values seem right to me.

My refugium is lit 24 hrs/day by a 250W MH. The fuge is located in the basement so I need the heat from the light to keep system temperature stable.

 

[clp]

Are you just putting Kalk in your tank, or are you dripping Kalkwasser. If you just dump it in your tank, your pH will spike up, and the alkalinity will be depleted. You must drip Kalkwasser slowly in a high flow area or it will not be effective. Your Alkalinity is at the low end of the range; I'd be shooting for 10+.

Curt

 

[OldmillXxX]

If I have low PH (7.8) and drip kalk( from kalk reactor to sump via float valve), will my PH stabilize over time? My sump/fuge is lit 27/7 and I do not have a large calcium need at this time.

 

[clp]

If your tank depletes the alkalinity faster than you are replenishing it, then your pH may remain low and have big swings.

Curt