PH monitor picking up " noise"

[minibowmatt]

I recently got a Hanna PH monitor. After installation, I was getting readings 3-4 points below what my test kits showed. After consultation with Hanna tech's it was determined I was getting electrical noise from my E- ballast that ran my MH and CF lighting on the system. They asked me to send it back to them so they could install a filter in the meter to stop that noise. (for free Smile ).
I got the meter back today, and I am still getting the noise=low PH readings (in the 5.4 range) When I test my tank water in a seperate cup, the meter reads correctly, 8.1-8.2. IMO it is no longer Hanna's problem, but mine.

With both ballast turned off, i get accurate readings from the tank. The CF ballast (only) is the worst- dropping PH to 6.3, and the Electronic MH ballast (only) drops my PH to 7.85 from 8.1/2.
SO I need our electronics gurus to help me to isolate the lights or the monitor from the system. I have tried plugging the monitor into a different circiut, but it still doesnt help. I am going to try a few other circuits tonight, but I dont think it is going to help.. Anyone have ideas on how to isolate them from each other?
Thanx!!

 

[pwj1286]

find out what frequency is being emitted from the ballast and determin the wave size of the frequency and construct "wire grill" out of metal (to go around the ballast) that has holes smaller than the wave size of the frequency you determined. This may effectively block out the waves from your ballast.

Its like your microwave oven grill that has a bunch of holes in it so you can see your food, but not receive harmful microwaves while watching your food cook. The waves bounce around in your oven and bounce off the grill because the waves are too large to go through the grill. Electrical interference is common with electronic ballast. Some people have told me that they cannot recieve FM signal from radio stations. So i predict the wave that is emited from most electronic ballasts is in the FM range.


lol I dont know if this will work, but its a shot. I think it will be unlikely to work like a microwave oven grill, but may atleast reduce the amount.
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[minibowmatt]

thanx... any idea how to determine the wave size? i am already building a box lined with lead sheet to stop any of this type of radiation...

 

[Anonymous]

Are the metal cases on your ballasts grounded?

I'd start there.

Do you have a ground probe?

Can you move the ballasts/ph mon further away from each other?

B

 

[minibowmatt]

the cases arent grounded yet.. that was a suggestion from another reefer too, so I will be doing that. I am also installing a grounding probe over the weekend.

 

[Anonymous]

Careful about using lead in a hot, salt air environment, It'll oxidise quickly and it cannot be good for a tank. (Sure that someone smarter will have something else to add.....)

 

[minibowmatt]

thanx for the posts. I ended up switching out the ballast for a Magnetic. It was my last option. I tried everything, and the ballast was giving off too much RF...

 

[bubblepuffer]

Did you try Aluminum Foils from you kitchen.. those are known to block signal and interference.. you want to try it..

 

[minibowmatt]

I already traded the offending ballast away.. No worries anymore.
I did try wrapping it in Lead and Steel wool, both didnt help.