Reefkeeper pH Probe/General Calibration - Keep Solution Packet In Tank Water?

[ChouDawg]

I picked up a BRS pH probe a month or so back and calibrated it once when I first got it, I decided to recalibrate it tonight while doing a water change. I have Pinpoint 7.0/10.0 calibration solution that I got recently from ReefGeek.

So I followed the DA instructions and navigated to my SL1 then the pH probe and hit calibrate. Beforehand I left the solution packets in the sump because I read you're supposed to calibrate it at tank temperature. I also had a cup of RO/DI for rinsing the probe before going into each solution and between solutions. Last time I calibrated I dropped it in the 7.0 solution and waited 12 minutes then moved to the 10.0 solution. It read fine when I switched back/forth afterwards between calibration packets.

This time I gave it a bit more time because I was finishing up a water change, give or take 15 min per solution. While doing the 7.0 I kept the 10.0 in the sump to maintain temperature but this got me to thinking...during those 15 mins or so doesn't the packet temperature drop significantly making the whole point of the original temperature floating moot? Should I be keeping the packets in the sump, hopefully without them tipping and calibrate that way? I don't want to waste another pair of solution till i get this process narrowed down.

[Octoman4]

Do not keep them in the sump to risky, the temp difference will not make it so you dont get an accurate reading. It is suggested that you have very similar temps, if its a few degrees off your fine.

[ChouDawg]

Hmm, okay wonder if maybe my pH probe is toast then. I brought it up because I noticed the temperature : pH conversion chart on the packet and the suggestion to keep the packets in the sump beforehand to match tank temp.

[DaveMorris]

All you need to do is actually know what the temp of the cal solution is. Then you can use the temp chart on the packet to adjust the reading accordingly.

[Octoman4]

There you go, Dave's got you set. Probes usually don't last longer than year. Sometimes they can but in my experience, they dont.

[ChouDawg]

I see the temperature chart but I don't think my RKL lets me adjust the calibration points, I'll mess with it some more and see though, thanks guys for the info.

[DaveMorris]

I see the temperature chart but I don't think my RKL lets me adjust the calibration points, I'll mess with it some more and see though, thanks guys for the info.

You should be able to adjust the target value on both the RKL and the RKE. I'll try to remember to look at my RKL setup when I get home tonight to verify that it will do it.

[knightnsd]

I just bought RKL plus and the confusion is beginning.

[ChouDawg]

You should be able to adjust the target value on both the RKL and the RKE. I'll try to remember to look at my RKL setup when I get home tonight to verify that it will do it.

I think you're right Dave, I have to double check as well. Would i then have to have a temp probe and a pH probe in my solution packet to set the value based on temperature, or am I over complicating it?

I just bought RKL plus and the confusion is beginning.

It's not too bad, the RKL is very simplified in my opinion than the Apex/Reef Angel controllers in terms of options/customization. If you have any questions about setup feel free to post in the controller forum I'll try to help you out. I remember when I set mine up a couple years ago there were a few things that irked me till I figured out settings other people used that worked out best. Off the top of my head ATO, temperature and some ports on the PC4 don't go completely "off" so some devices may behave funky on these ports I believe its 1-2 but varies sometimes.

[DaveMorris]

The PC4 channels 2 and 3 are solid state triads and very small current devices like Aqualifter pumps and some powerbeads will not shut off, even though the RKL/RKE head unit says that the channel is off. You can either use a surge protector on those channels or just move the device to channel 1 or 4 and that problem will not happen. Channels 1 and 4 are mechanical relays and they are not susceptible to this problem.

[DaveMorris]

Here is where you can find the latest user guides for the RKL and RKE:

http://www.digitalaquatics.com/support/

[ChouDawg]

Thanks Dave for clarifying which PC4 ports were solid state relays, I have my ATO Aqualifter on port 4, I remember when I first set it up I had it on 2-3 and it wouldn't shut off, had a few "oh " moments till I read up on it.