Huge pH drop when sump return pump is running

Basic / Standard Reef Angel hardware
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leadguitarist05
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Joined: Mon Mar 09, 2015 6:00 am
Location: Anderson California

Huge pH drop when sump return pump is running

Post by leadguitarist05 »

I just finished installing my Reef Angel and I couldn't figure out why my pH never seemed to be above 6 no matter how many times I recalibrated it. I tried testing my pH in a cup of tank water and discovered it was reading 7.9, but in my tank it will read anywhere from 2.3 to mid 7's and fluctuate constantly. I discovered that when I turn my return pump off (a Mag Drive 7) my readings are normal +- 7.9, as soon as I turn on the Mag Drive it drops to around 5 (usually). I tested for current leakage in the water, my total current leakage is about 4 volts and the Mag Drive is only responsible for about 0.5-1 volt. I tried adding a grounding probe to see if it would correct the pH readings and it hasn't helped, but there is no measurable current in the water with the grounding probe.

I did purchase my Reef Angel second hand on Ebay (got an amazing deal on it). Today I ordered a Bulk Reef Supply lab grade pH probe before I realized that the drops coincided with turning my pump on. I previously thought the pH probe was just old and faulty...

Is there any chance that the amp load on the relay box is causing a problem with the pH readings? It doesn't seem to me like the small amount of current leaking from the Mag Drive should be the problem... however, I did just order a Jebao DCT 8000 to replace it with :|
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lnevo
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Re: Huge pH drop when sump return pump is running

Post by lnevo »

That's exactly what current leak will do.
leadguitarist05
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Location: Anderson California

Re: Huge pH drop when sump return pump is running

Post by leadguitarist05 »

lnevo wrote:That's exactly what current leak will do.
Even though every single piece of equipment I have is leaking some current? Even my pH probe is leaking 0.5 volts... Any idea why the Mag Drive is the only one that seems to be causing the pH readings to be wacky?
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lnevo
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Re: Huge pH drop when sump return pump is running

Post by lnevo »

It is not normal. You should not be leaking so much current. It could be the frequency (just guessing).
leadguitarist05
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Joined: Mon Mar 09, 2015 6:00 am
Location: Anderson California

Re: Huge pH drop when sump return pump is running

Post by leadguitarist05 »

lnevo wrote:It is not normal. You should not be leaking so much current. It could be the frequency (just guessing).
It can be hard to find consistent opinions on an acceptable level of current leak, someone on a different forum said a few volts is no big deal and there's no need to worry unless it's 40 volts or more, another person says the source of any voltage leak at all should be removed, another said that if you use fluorescent lighting there's always going to be stray current... I was thinking although it's only leaking <1v, maybe the Mag Drive is leaking a higher amount of amps... I suppose as long as replacing it with the DCT 8000 Jebao fixes the problem it won't make a whole lot of difference.

Do you know if we're able to control the Jebao DCT series pumps yet?
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lnevo
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Re: Huge pH drop when sump return pump is running

Post by lnevo »

No, but someone is trying to work something out.
leadguitarist05
Posts: 20
Joined: Mon Mar 09, 2015 6:00 am
Location: Anderson California

Re: Huge pH drop when sump return pump is running

Post by leadguitarist05 »

So I installed my new Jebao DCT 8000 only to still have the same problem... and this is a DC pump... any ideas? I think I'm going to try unplugging it from the relay box and see if it does the same thing when running directly from the wall socket...
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cosmith71
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Re: Huge pH drop when sump return pump is running

Post by cosmith71 »

Maybe it's something in your tank that only has an electrical path when the water is coming down the overflows? Try sticking the probe in your tank instead and see what happens.
leadguitarist05
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Joined: Mon Mar 09, 2015 6:00 am
Location: Anderson California

Re: Huge pH drop when sump return pump is running

Post by leadguitarist05 »

cosmith71 wrote:Maybe it's something in your tank that only has an electrical path when the water is coming down the overflows? Try sticking the probe in your tank instead and see what happens.
I have been checking it both in my sump and my tank, turning everything off and on one at a time... the whole 9...

I am pleased to announce that I just figured it out... One of my float switches for my ATO went bad and was causing the problem... Still don't know why it only went wacky when my return pump was running, but tonight I realized my ATO had stopped, just now thought maybe it had been shorting out inside the sump this whole time, pulled the float switches out altogether and bam! pH registers completely normal! I'm going to change my ATO to use the water level sensor instead...
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cosmith71
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Re: Huge pH drop when sump return pump is running

Post by cosmith71 »

Awesome! I forgot about the float switches.

--Colin
leadguitarist05
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Re: Huge pH drop when sump return pump is running

Post by leadguitarist05 »

cosmith71 wrote:Awesome! I forgot about the float switches.

--Colin
Yeah, I think I'll use the water level sensor in my sump and the one good float switch in my ato reservior to alert me when it gets low.
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