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jjoos99
08/12/2017, 07:49 AM
I was just wondering if there was anyone who is dosing kalk to maintain a consistent ph level having a controller add kalk when the ph level drops to a preset level and shut off at the upper preset level? I fight chronic low ph, I think due to my ca reactor and excess co2 in my home. My night time levels will go as low as 7.6 and without adding kalk my daytime levels might reach 7.9. I thought about having my apex add kalk at say 7.9 and shut off at 8.0 and let my daily swings due the rest.
I do have my skimmer intake plumbed outside and leave a window cracked open when I can.
thanks
Jeff

bertoni
08/12/2017, 08:50 AM
You might be able to keep the tank's pH a bit more stable, but the calcium and alkalinity levels would drift more, as will the SG. I consider those parameters more important than pH.

Dan_P
08/13/2017, 06:44 AM
You might be able to keep the tank's pH a bit more stable, but the calcium and alkalinity levels would drift more, as will the SG. I consider those parameters more important than pH.

Agreed, but if you frequently measure specific gravity, Ca and alkalinity for a month while automatically titrating your system with kalk to maintain pH, you will have the data to understand the risk of these parameters going beyond limits while maintaining pH. I hope your controller is reliable and won't overcharge kalk.

Dan_P
08/13/2017, 06:46 AM
Agreed, but if you frequently measure specific gravity, Ca and alkalinity for a month while automatically titrating your system with kalk to maintain pH, you will have the data to understand the risk of these parameters going beyond limits while maintaining pH. I hope your controller is reliable and won't overcharge kalk.

Oh yeah, one more very, very important point: your pH probe must be calibrated often to ensure you don't overcharge kalk. Undercharging isn't an issue.

bertoni
08/14/2017, 03:19 PM
If you want to tinker, you could consider using Kalkwasser and plain RO/DI for auto-topoff, and use the controller to choose between them based on pH. There's more risk of problems with a more complicated setup, though.

jjoos99
08/14/2017, 07:49 PM
If you want to tinker, you could consider using Kalkwasser and plain RO/DI for auto-topoff, and use the controller to choose between them based on pH. There's more risk of problems with a more complicated setup, though.

Here is my thinking. My ro/di is currently hooked directly to my ato and I use a solenoid that the ato controls when needed. I am thinking of controlling one solenoid valve with my apex off a float switch and have it maintain say 8.0 and once it reaches 8.01 apex will switch over to the second solenoid and float switch to control my water level. I dont think it would take a lot of kalk to keep it at least 8.0 I would have to watch my alk level at first to get my ca reactor set to go with the kalk.
thanks
jeff

jda
08/14/2017, 07:58 PM
I would not trust a hobby grade PH probe to add kalk to your tank. They are can drift and fail. It is just not worth it since not that much kalk can crash your tank.

karimwassef
08/14/2017, 08:13 PM
I have been using pH probes to add Kalk for years. However I don't do it to maintain pH. I do it to maintain Alkalinity.

I've tracked both pH and Alkalinity and I can maintain my Alk level by maintain pH IF I maintain an adequate gas exchange with outside air through my power air injectors. and I do mean POWER AIR INJECTORS.

I also have significant evaporation with metal halides and heavy airflow.

Does it work - YES. Can everyone do it - IMO not unless you have heavy air injection and high evaporation rate.

I do calibrate monthly and I use two pH probes to capture deviations. One is the loop probe, and the other is the deviation control probe. Both would need to fail together.

jjoos99
08/14/2017, 09:45 PM
I have been using pH probes to add Kalk for years. However I don't do it to maintain pH. I do it to maintain Alkalinity.

I've tracked both pH and Alkalinity and I can maintain my Alk level by maintain pH IF I maintain an adequate gas exchange with outside air through my power air injectors. and I do mean POWER AIR INJECTORS.

I also have significant evaporation with metal halides and heavy airflow.

Does it work - YES. Can everyone do it - IMO not unless you have heavy air injection and high evaporation rate.

I do calibrate monthly and I use two pH probes to capture deviations. One is the loop probe, and the other is the deviation control probe. Both would need to fail together.
Where can I find some info about the power air injector? If might just be what I need to rid my tank of excess co2 that is probably pulling down my ph.
thanks
jeff

bertoni
08/15/2017, 03:35 PM
A good skimmer should be enough along with a water surface that has a good rippling motion should be enough for removing carbon dioxide generated in the tank, at least for most setups. A tank with a very heavy fish load might be an exception.

karimwassef
08/15/2017, 10:30 PM
I built my own. It's not hard to do. It's basically a penductor inside of a PVC coupling with a T to let air get sucked in. The only real cost is a high pressure pump, but I'm using the Jebao 18000 which is under $200 now.

I'll look for my protein skimmer design thread where I show the penductor fitting design.

karimwassef
08/15/2017, 10:34 PM
the pump
http://www.reefcentral.com/forums/showthread.php?t=2634328

the injector
http://www.reefcentral.com/forums/showthread.php?t=2637568

the skimmer running
http://www.reefcentral.com/forums/showthread.php?t=2229274&page=14

the skimmer maintenance
http://www.reefcentral.com/forums/showthread.php?t=2571877

the skimmer design
http://www.reefcentral.com/forums/showthread.php?t=2229274&page=13

http://i1062.photobucket.com/albums/t496/karimwassef/ps6_zps85782da6.jpg

karimwassef
08/15/2017, 10:35 PM
A good skimmer will work, but the penductor injection pulls in gallons of air and churns it aggressively. This is the same mixing technology used in firehoses and industrial mixers.

tmz
08/18/2017, 12:26 PM
You might be able to keep the tank's pH a bit more stable, but the calcium and alkalinity levels would drift more, as will the SG. I consider those parameters more important than pH.

I think pH is important but not at the expense of constancy in alk and sg . Dosing kalk at an even rate over 24 hours will keep the pH higher anyway without sacrificing constancy in other parameters. If that's not enough increasing air exchange , ensuring fresh air to the wat or a CO2 scrubber can raise it more.