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hkgar
07/18/2017, 01:19 PM
I saw some instructions for setting up a calcium reactor and the suggestion was made to add a command line to shut down if ph of the tank is less than 7.8. Anyone one do this?

My ph routinely drops to 7.5 so I might consider it, although it would change the dosing requirements.

bertoni
07/18/2017, 06:10 PM
I've heard of people adding that check, and I'd do something if the pH of my tank was actually at 7.5. Are you sure that the measurement is correct? There are a lot of problems with pH measurement reported here. I'd recalibrate the probe and check it for electrical interference.

five.five-six
07/19/2017, 07:03 AM
Not only did I have my Ca reactor shut down with low PH, I had a small pump add kalkwasser from a 5 gal bottle when ph dropped, back when I had a larger tank.

hkgar
07/19/2017, 08:09 AM
I've heard of people adding that check, and I'd do something if the pH of my tank was actually at 7.5. Are you sure that the measurement is correct? There are a lot of problems with pH measurement reported here. I'd recalibrate the probe and check it for electrical interference.


I calibrated the probe last week and again two days ago. I rechecked with the Salifert kit - pretty old - and it looks between 7.4 and 7.7.

ca1ore
07/19/2017, 11:34 AM
Right, so double or triple check your probe (and make sure to 'save changes' if doing it via apex). Also, check and see if tank pH is actually affected by your CaRx. I run one, but it doesn't affect system pH all that much, thus no shut off.

tmz
07/19/2017, 12:02 PM
When I ran a calcium reactor , I also dosed fully saturated kalk from a still reservoir via peristaltic pump. I did not use a shut off for either ;both ran 24/7 . By adjusting the out puts of each (Ca reactor by adjusting the CO2 input and kalk dosing by volume set for 24 hours ) , I was able to maintain stable pH , in the 8.2 to 8.35 range . Ultimately I put the Ca reactor on the shelf ( about 8 years ago and met the needs for alk and calcium via only kalk with a bit of tweaking with 2 part .

hkgar
07/19/2017, 02:50 PM
I have the reactor shut off for 24 hours and ph is 7.63. Not much change and I re-calibrated the probe and nothing change. And, yes I did it with Apex and it reported successfully updated.

I have be lights out for the last 48 hours to control a bit of Cyano.

I might try just using Kalk in the ATO water, but evaporation varies somewhat daily and is to a degree dependent on the season. My evaporation was over six in the winter and is about 4.5 now.

tmz
07/19/2017, 03:57 PM
I use kalk at a preset daily dose ( adjusted seasonaly) broken into equal increments every 9 minutes or so over 24 hours. Using it in top off will as noted result in seasonal variations and less efficient dosing.

bertoni
07/19/2017, 06:41 PM
Have you checked for electrical interference? The Salifert numbers might be off, and having two kits fail is uncommon, but not impossible. If that pH range is correct, I think that looking into Kalk and fresher air is a good idea.

hkgar
07/20/2017, 01:03 PM
Have you checked for electrical interference? The Salifert numbers might be off, and having two kits fail is uncommon, but not impossible. If that pH range is correct, I think that looking into Kalk and fresher air is a good idea.

Electrical interference? Ya think just maybe

https://photos.app.goo.gl/vWCb1Dek73yC4KRd2
https://photos.app.goo.gl/FYa3brNHBuZeKjup2

How much variance could it cause and best method to prevent?

I have trie isolating my SG probe with the module at the top and running the probe over the top

bertoni
07/20/2017, 03:29 PM
The variance from electrical interference can be quite large, certainly enough to move your pH into a more acceptable zone. Preventing it can be a problem. Sometimes a ground probe helps; sometimes keeping power and probe wiring physically isolated makes a difference. It's possible that some piece of electrical equipment is causing problems.