UV and PH question

[cruzersmith]

So I did maintenance to scrape the glass and vacuum the sand of the brown stuff I’m thinking is Dino’s. I have an old 40Watt aqua ultraviolet sterilizer I thought I would run to see if it helped knock down the return growth. Suddenly my hydros is alarming and I’m getting readings in the 11s up from the high 7s to 8. So I recalibrated the probe and still getting the high PH. So I turn off the UV and the pump feeding it and the probe reads normal. I watch the readings as I turn it back on and up go the numbers into the red. So being a novice with using this in saltwater I don’t get what’s going on. Any insight would be greatly appreciated. Thanks.

 

[Tatted Reefer]

Is it possible the High Output from the UV is throwing your probe off? Is there any way to temporarily reroute the Probe wire away from any other wires? Like running it to the front of the tank just to see if it makes a difference

 

[cruzersmith]

While I assume it’s possible I can’t say. The probe wire is as far back as possible with the UV as far forward as possible. I’m wondering as the body is plastic if it’s possible that there is a static charge. Otherwise maybe something with the pump?

 

[Tatted Reefer]

Just a thought. I remember reading about quite a few people having the issue with Neptune controllers. I'm not sure if it carries over to HYDROS or not. Seems like it would have to be some kind of interference for it to be changing so dramatically with the addition of the UV alone.

 

[Randy Holmes-Farley]

It is likely electrical interference. Turn off the UV and pump while watching the pH reading. Any instant change is electrical interference.

 

[PaulErik]

I agree it’s an electrical interference problem. Have run into this problem many times. The high operating frequency and ballast grounding is the problem with many Aqua Ultraviolet UV units. The grounding issue is a manufacturing issue. Just having the cables far from the controller/probes may not resolve the issues.

 

[MonsoonMan&RainChild]

I agree it’s an electrical interference problem. Have run into this problem many times. The high operating frequency and ballast grounding is the problem with many Aqua Ultraviolet UV units. The grounding issue is a manufacturing issue. Just having the cables far from the controller/probes may not resolve the issues.

Hi Paul,

Im working through this exact issue currently. My pH probe goes haywire when I turn on my Aqua Ultraviolet UV sterilizer. I've moved the cables etc to no avail. Per hydros, I took the probe out and placed it in a cup of water as a test and experience no issue when I turn on the UV which confirms electrical interference coming from the UV. When tested with a multimeter, it seems Im getting 0 volts when the UV is off and 4 volts when the UV is on.

What's the next steps? A grounding probe? A new UV? Or when you say its a manufacturing issue, should I be contacting Aqua UV with a warranty claim?

 

[PaulErik]

In my own situation the ballasts/transformers were the problem. The interference caused my ph and temperature probes to act up. I tried having all the cords separate and as far as possible but still had issues. After investigating further I found the ballasts inside the transformer casings were not grounded. They might do that on purpose so they don’t trip GFCIs so easily but the ground helps limit interference. I ended up replacing the ballasts with commercial grade units and grounding them. That fixed the issues I was having. I have many Aqua UVs in use and my problem was mostly with the 40 Watt units.

Your situation sounds different if you are not seeing the problem with the ph probe isolated (in a cup of water). That does indicate induced/leaking voltage from the UV. A grounding probe with GFCI protection may help with that.

 

[MonsoonMan&RainChild]

In my own situation the ballasts/transformers were the problem. The interference caused my ph and temperature probes to act up. I tried having all the cords separate and as far as possible but still had issues. After investigating further I found the ballasts inside the transformer casings were not grounded. They might do that on purpose so they don’t trip GFCIs so easily but the ground helps limit interference. I ended up replacing the ballasts with commercial grade units and grounding them. That fixed the issues I was having. I have many Aqua UVs in use and my problem was mostly with the 40 Watt units.

Your situation sounds different if you are not seeing the problem with the ph probe isolated (in a cup of water). That does indicate induced/leaking voltage from the UV. A grounding probe with GFCI protection may help with that.

Thank you, I think thats what I''ve gathered as the best path forward. Im ordering one and will replace the outlets with GFCIs and let you know how it goes. Thanks!