Low PH Apex Probe

[Orion]

Just picked up a PH probe for my apex, calibrated it according to the instructions in the apex manual. Used 7.0 for the low PH and 10.0 solution for the high end. My Apex is currently reading 7.18 and slowly dropping for PH.

 

Other parameters are -

Alk - 10.0

Calcium - 450ppm.

 

Is it possible for my PH to be that low, or should the probe be re-calibrated again? The numbers during calibration were close to 7.0 and 10.0 respectively.

Unfortunately I don't have a test kit for PH at the moment to compare.

 

I haven't tested for PH in awhile, but all the livestock including corals have been fine.

[Orion]

Quick update - I re-calibrated again, but PH still shows on the low side - 7.5

 

Bad probe?

[Coral Hind]

Check the probe connector to make sure it is clean and seated properly. Shake the probe while in the water to make sure air bubbles are not trapped on the bottom, that can cause a false reading. Even with a high alk you can still have low ph. Have you aerated the water outside to make sure you don't have a build up of CO2 causing the ph to be suppressed? I still have an ACIII not an Apex but on mine I can select temperature correction do you have that function with an Apex?

[Orion]

Check the probe connector to make sure it is clean and seated properly. Shake the probe while in the water to make sure air bubbles are not trapped on the bottom, that can cause a false reading. Even with a high alk you can still have low ph. Have you aerated the water outside to make sure you don't have a build up of CO2 causing the ph to be suppressed? I still have an ACIII not an Apex but on mine I can select temperature correction do you have that function with an Apex?

 

Checked the probe connection to the aquabus. Took it off, and put it back on now it reads 7.10. :/

 

I also shook the probe in the tank water. Yes, the apex does have temp correction. I don't have it enabled at the moment.

 

Never have aerated the water outside, but my water for water changes is always aerated, moving with a pump, and heated. It usually sits that way for a week before I use it.

 

Should I try re calibrating one last time since I am getting a different reading on the display?

 

Fwiw - I found my API PH test kit and it shows 8.0-8.2 on color card.

 

 

[Coral Hind]

I would enable temp correction and calibrate again. It does sound like a bad probe. I've gotten bad ones before too. I would expect it to be a little low only because of the time of day.

[Orion]

I would enable temp correction and calibrate again. It does sound like a bad probe. I've gotten bad ones before too. I would expect it to be a little low only because of the time of day.

 

Will Neptune or BRS send a new one if its bad?

[Coral Hind]

BRS replaced mine for me. I would give them a call or email on Monday.

[Orion]

BRS replaced mine for me. I would give them a call or email on Monday.

 

Great. Thanks for your input. Just wanted to make sure I was doing everything correctly.

[Orion]

I re-calibrated once again and turned on temp correction. Now reads 7.96. Is this acceptable? I read 8.3 is best.

 

Thanks so much CH!

[Coral Hind]

7.96 is normal to me for early in the day. It should increase as the corals/algae produce oxygen. Check it out later today to see where it is. Yes, some say 8.3 but if your house is well sealed the tank can build up CO2 which lowers the ph. If you think you have CO2 build up just take a cup of tank water and bubble with an air stone outside for about 30 minutes then check it. If the ph value increases then the CO2 in the house was holding it down.

[Orion]

Has not risen that much... 8.05 during the day. I have a glass top on the tank which could also be preventing O2 from getting in the tank. I'll try the outside air test, and see what I come up with.

 

[Coral Hind]

Glass tops really prevent oxygen exchange. If you remove that you should see a nice increase.

[Orion]

Glass tops really prevent oxygen exchange. If you remove that you should see a nice increase.

 

I turned the A/C on in the house. The air seemed a little stagnant in the basement. pH is now reading 8.3. Top is still on too.

[Coral Hind]

That sounds good. The air changing with the added air circulation sounds like it helped. Removing the lid would still help some. Is that an option?

[Orion]

That sounds good. The air changing with the added air circulation sounds like it helped. Removing the lid would still help some. Is that an option?

 

I wish it were. My wife is paranoid one of the clowns may jump out of the tank. Unfortunately since the glass is curved slightly putting a screen top isn't ideal either. What if I ran a small air stone?

[Orion]

Just discovered something interesting. It appears my main pump is causing some EMI with the pH probe. When the pump is off, the apex reads 8.3. When the pump is on, it reads 8.0.

 

I tried moving the ph probe away from the pump, including the probe cord.

I also tried removing the stock pump, and replacing it with a small maxijet. I still saw a .10 drop in pH, but not as bad as the stock pump.

 

Bad probe? Anyone ever heard of this before?

 

 

[rtsusc83]

The probe and cable are sensitive to EMI. If you can separate the cabling from other wires and place the probe away from the pump. I had the same problem and read elsewhere of the same issue.

[Orion]

The probe and cable are sensitive to EMI. If you can separate the cabling from other wires and place the probe away from the pump. I had the same problem and read elsewhere of the same issue.

 

I moved the probe and cable away as far as I could from the other cables. The drop in pH when the main pump/skimmer is on is now only .10. Since I have a small tank I cant run the wire any further. I may try using a choke on the probe and see if that helps any. Radioshack has them I believe.

[Coral Hind]

I wonder why they don't make the cables shielded since they are so sensitive. The choke magnet is a good idea. Let us know how that works.

[Orion]

I wonder why they don't make the cables shielded since they are so sensitive. The choke magnet is a good idea. Let us know how that works.

 

Now I'm not sure if the pH probe is just broke or what. It showed 8.1 this morning, and now shows 8.8. Tested with API kit, and that shows 8.0-8.2 range. Going to see if BRS can send a replacement anyway.

[Coral Hind]

Try to calibrate it again since you moved it. Maybe when you calibrated it before it was getting EMI which threw off the calibration. Just a guess.

[Orion]

Try to calibrate it again since you moved it. Maybe when you calibrated it before it was getting EMI which threw off the calibration. Just a guess.

 

I would if I had anymore calibration packets left. I'll pick up some while I'm out of town this week. In all honesty I think there is a problem with the probe itself, as well as an EMI issue as it now spiked to 10.0 this morning. Hopefully BRS sends a replacement.

 

This also makes me wonder about the accuracy of the temperature probe, and if there is EMI going on. I haven't bothered to double check what the temp probe has been reading with another thermometer. I'll do that when I get home as well, and put a ferrite core on the temp probe if needed.

 

Has anyone else run into EMI issues with other controllers/probes?

These EMI issues IMO are ridiculous. For the money I spent on this controller, this should not happen. As someone stated above, Neptune needs to make better quality cables.

 

[rtsusc83]

No problems with my Temp probe as it checks out with my chiller temps. From what I understand, the pH probes are sensitive to EMI. I check my pH trends using the Apex graph feature to watch for any unusual trends and so far I have used it to determine when to calibrate and replace my probe. My first Apex brand pH probe lasted 14 months. So, from what you are saying, sounds like your probe is suspect. I like the Apex system and I know and understand your frustrations. But I hope that after your pH problem is solve you will learn to appreciate the Apex system.

[Orion]

Alright I think I have it all figured out.

Back home now from being on the road since Sunday. My last water change was on Saturday, a 20% change. I put ferrite cores on the pH probe, and the other equipment. Recalibrated the pH probe, and my tank is officially sitting at 8.0. No more EMI issues!

 

This sounds about right. Is it ideal? Maybe, maybe not. I would like to see around 8.2-8.3

 

Here were my water parameters after Saturdays WC -

 

Calcium 450ppm

Alk 10

Mg 1350

Salinity 1.025

Temp 79

PH 8.0 (API Test Kit)

 

5 Days later

 

Calcium 430ppm

Alk 8

Mg 1300

Salinity 1.025

Temp 79

PH 8.0

 

Is it time to start dosing 2-part, or will a weekly water change be sufficient for now?

[Coral Hind]

After you do the water change is it back to where it was the week earlier or is it slowly drifting down? If the water changes are enough to keep it stable week after week then I would just stick with that. Or dose two part and do 20% water change every other week. Not doing water changes so often saves time, water, salt, and effort. I would get a doser for the two part. The more you can automate the more time you can enjoy the tank more.