Stray voltage

[rimai]

The dips in the client is related to the client I think.

[ReEfnWrX]

Not sure I understand this so wanted to ask a question. I have the standard Reef Angel Plus (extra memory I guess, right?) and it the pH unit built in. Ironically reading the boards today I came across this and while I've not measured for stray voltage (I'll check tonight) I am seeing random spikes in my pH reading on the ReefAngel Client (v3.0). I'll see a pretty regular graph and then all of a sudden it will dive down to 6 or so then right back up to 8 or whatever it is at.

So in this case and having the pH on the controller itself how do you or do you need to run with Galvanic isolation? Or am I mixing something up here altogether (which is probably the case).

Roberto can correct me if I am wrong. But if I understood him correctly, there is Galvanic isolation in the pH expansion unit but not in the base pH port on the RA unit.

It would be interesting if someone with a pH expansion unit who thinks they may have or used to have stray voltage would test their pH in the tank and in a cup of water with the base pH port and do the same test using their pH Expansion port.

I do plan to buy a pH expansion very soon as galvanic isolation is supposed to prevent the affects of stray voltage on Probes readings.

[rimai]

Keep in mind that the stray voltage is not coming from the probe.
It's originated in one of your equipment that is plugged into RA. Usually powerheads, heaters, pumps, LED drivers or even a PC computer.
The probe is just providing a point of differential voltage and completing the circuit.
If you have any other point of differential voltage dipped into the water, you would still get the stray voltage, regardless of the probe being in the water or not.
So, you are only treating the symptom by isolating the probe. You are not treating the cause.
It's the same analogy when you dump chemicals or shut the lights off to kill algae in your tank. You are simply treating the symptom.
The best is to identify which equipment is the problematic one and remove/replace it.

[ReEfnWrX]

This is true and I agree, however... Majority of times when stray voltage is a factor it is coming from a main pump which typically cost a decent amount of money.. Every return pump I've had has caused stray voltage after a couple of months and I do not think it is worth it to replace a $100+ pump every couple months.

From my research, the only time stray voltage is to be of concern is in two situations.

1. You use probes that do not have galvanic isolation and therefor the reading will be affected slightly.

2. If your tank is not grounded every time you touch the tank and feel the current or a shock... You are not the only one feeling it, everything that is living in your tank feels it as well, because you are completing the circuit and allowing the current to leave the tank water.... Which is why it is very important to at least get a grounding probe so you are not affecting your livestock every time you touch the tank water.

[bmhair03]

Roberto what is the meanwell connection if any?. My ph reading drops 2 points when my lights come on. Going to recal but still think it's linked to lights.

[rimai]

You are not the first one to complain about this and their drivers.
Did you replace any drivers recently or still original drivers?

[bmhair03]

I believe I switched one out. Others orig. Don't remember which one.

[rimai]

I think they changed something along the way.
Do you know which one is the new one?
The new dimming modules have optical isolation to avoid this problem.

[bmhair03]

Yes I figured it out. But what would be the fix if any.

[rimai]

Optical isolation, which the new dimming modules have.

[chapboogie]

I have the new dimming module, and it fixed mine.

Sent from my SCH-I535 using Tapatalk

[bmhair03]

I think I'll try the old driver. I think I replaced it but it was a matter of too many led shorted out
In the end. Thanks for the heads up. If not then I'll order one. Thanks

[RootsRockReefer]

Are you using meanwell drivers?

What do you believe meanwell drivers induce to the ra ph probe readings?

[rimai]

Old meanwell drivers didn't do that.
Somewhere along the line, they changed something that started introducing stray voltage into RA through the dimming signal wire.

[RootsRockReefer]

Old meanwell drivers didn't do that.
Somewhere along the line, they changed something that started introducing stray voltage into RA through the dimming signal wire.

I will unplug my LED set up and pull the dimming lead tomorrow and see if the PH probe acts normal. Its reading is absolutely unpredictable on a newly set-up controller.

I have bulk lab grade ph7 & ph10 solution. No matter how long I leave the probe in the solution the reading drifts upward?

Is the only way to avoid the galv isolation problem to get the PH expansion module? This should be mentioned in the description I feel misled, why should I buy a ph expansion when we are already sold a PH port?

[chapboogie]

The dimming expansion will solve the problem. It isolates the dimming lead from the ph.

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[RootsRockReefer]

So if I simply removing the dimming leads from my LED drivers to the main unit, the PH probe should operate normally then, correct? This would completely remove the only dimming circuit I am using.

[chapboogie]

Probably, but that will also make your lights not work.

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[RootsRockReefer]

So its official in my case, within a minute after pulling the dimming leads off the Relay Box the PH reading went from its 2.45 to the more expected 7.98. Re-calibrated the probe for kicks came in at 8.21 which is right in line with my standard PH test kits reading. After an hour the reading was still basically steady reading like 8.17 to 8.22. Pushed the dimming leads back on the relay box the PH reading within a matter of moments was back down to the 2.54 level.

Dimming module is the key i suppose,

[paulvisco]

I was running into to same issue last night with the low PH reading (6.00) in the test solutions it was 7.00 and 10.00 put some tank water in a cup and that was 8.00 but probe in the tank and it went down..

Turned out to be a ATO float switch was causing the leak and the bad readings. with Roberto's help last night we had it fixed in about 10 minutes..

Thanks all for the quick turnaround on problem solving...

[neuro]

I was running into to same issue last night with the low PH reading (6.00) in the test solutions it was 7.00 and 10.00 put some tank water in a cup and that was 8.00 but probe in the tank and it went down..

Turned out to be a ATO float switch was causing the leak and the bad readings. with Roberto's help last night we had it fixed in about 10 minutes..

Thanks all for the quick turnaround on problem solving...

how did you fix it? i have the same problem. i even bought new ATO switches, which helped initially until it failed again.

[paulvisco]

I was running into to same issue last night with the low PH reading (6.00) in the test solutions it was 7.00 and 10.00 put some tank water in a cup and that was 8.00 but probe in the tank and it went down..

Turned out to be a ATO float switch was causing the leak and the bad readings. with Roberto's help last night we had it fixed in about 10 minutes..

Thanks all for the quick turnaround on problem solving...

how did you fix it? i have the same problem. i even bought new ATO switches, which helped initially until it failed again.

good water proofing on my splices for the cable.. I used shrink with hot melt glue in it so that it creates a water tight splice. my original problem was the leads were spliced just above the water line and salt creep and water caused the path to the circuit

[Themaddhatter]

Just encountered a similar problem last night as soon as I hooked up my reef angel plus. I only have the standard temp probe and a brand new pH probe for sensors, and the main relay box with 2 heaters, 2 powerheads, 2 return pumps, and my lights and skimmer hooked up. The lights are non dimmable. I'll take readings tonight. The equipment was all already running and I had my hands in the tank prior to changing our to the RA+. The pH probe itself shouldn't produce voltage should it?