Blue Electrical sparks in sump?!?!

[ReefFrenzy]

Ok so here is a new one for me.....

First a little background on the tank: I have a 180 gallon Starfire glass FOWLR tank with 55 sump that has been up over a year and running smoothly. It has a Mag 9 return pump, Mag 3 pump on 57 watt U/V @ 165 GPH, Bubble Magnus Hero 180 Skimmer, a Bulk Reef GFO/Carbon reactor, with cobalt MJ1200, and as of last week a BioPellet reactor added with a Cobalt MJ 900. All of this is housed in the sump and there are two Koralia Evo 1450 PH up top, as well as a pair of 100W heaters, one in each over flow.

So this morning I wake up at about 7:00 and hear the MJ1200 "singing" a little bit as it will do if it drops from its normal resting place on the filter sock and leans on the skimmer. I open the cabinet and see that on the egg crate stand for the skimmer, there are little blue "fireflies" darting around at different spots about every 4-6 seconds.

I look around to see if the VCR or anything else has a blue LED indicator on it and there is not. The room is pitch black. I peer into the sump and see that inside the skimmer right where the vertical tube is to adjust the flow, there are a few more of what I now determined to be electrical sparks "arching." I found it odd that there would be arching going on, inside a closed system without a + and - pathway, but I am not an electrician.

My next move is to get my digital volt meter and plug one probe into the ground terminal on the extension cord and the other probe goes into the tank. I'm getting 45 volts of measured electricity, and I checked it 4 times.

Obviously I need to start unplugging devices one at a time, to isolate the offending piece of equipment that is leaking electricity. Just for kicks I walked into the other room and checked my 90 reef tank with sump and similar equipment as my 180, minus the UV and Biopellets. The 90 Reef is reading 33 volts.

So I was wondering for those of you that have checked your tanks for stray voltage, what have you found to be a "typical" level? From what I have read on the subject it is difficult to get to dead zero with all the pumps and things we have in the water. My fish in either system seem no worse for wear, however the long term effects could be deleterious, with stray voltage blamed for HLLE.

So has anyone else ever looked into your sump in the dark?

(As an aside I'm not trying to start a "grounding probe with GFCI verses running without one" debate. There are hundreds of threads out there regarding both points of view and you are free to chose which ever method works for you.)

I'm curious what voltage readings people have been getting in their tanks.

Thanks,

Larry

 

[LostintheDark]

I have a 225 reef and fish with a 75 sump and all the related goodies. I measure 28 volts. When I try to locate the culprit it seems everything adds a few points. I unplugged everything one by one and each appliance dropped the reading a little. I went nuts reading about it with all the associated arguments but in the end decided to leave everything alone as the tank has been running great and everything looks healthy.

 

[reefer gladness]

Got me curious so I got out the multimeter. 58gallon tank with 20 gallon sump, external Eheim return pump, 2 Vortech pumps, a Reef Octopus skimmer in the sump. Grounding probe and no GFCI.

I measure 0.4 volts and wasn't able to isolate that. Tried removing the grounding probe and turning off the pumps with no change. I'm assuming that's completely normal, although not sure where it's coming from. I know it takes a small amount of energy to activate a muscle from a resting state so it could just be bioelectricity.

 

[DaveK]

The .4 volts reefer gladness is getting, I wouldn't worry about. The 28 volts and 45 volts may represent a major problem that should be corrected.

I suspect that in the case where "...it seems everything adds a few points ..." there are multiple points of failure and they should be corrected.

Every time I found stray voltages that high I found a problem. Usually it was in a cord. SW takes it's toll on plastics and over time cord get hard and brittle. Finally they crack exposing the wire inside.

Another quick test you can do is to get a GFI adaptor and see if what you plug into in trips the GFI. If it does, it's likely bad. As a note, some types of lighting that uses high frequency electronic ballasts will trip GFIs even if they are good. So if your testing lighting, consider that you can sometimes see "false positives".

 

[ReefFrenzy]

Thanks Davek,

I DO have a GFCI adapter that I often use when using a shop vac or anything else that is around water. I am going to start testing devices tomorrow to see what is leaking voltage. I have a 9" Dogface puffer, so maybe he nipped the koralia powerhead cord.

Can anyone elaborate on why there would be arching in the sump from plastic parts to other plastic parts, i.e. the gaps in egg crate?

I mean if the sump is suspended off of my hardwood floors, on a second sub floor inside my stand, why would their be arching?

Larry

 

[PIMPALA]

You have a mag 9 for return, and a pair of MJs in a 180?? Did I read that correctly?


Sorry, I don't have any electrical help, other than id check the equipment closest to the arcing first. I'd be less concerned about the voltage and more concerned about finding what's arcing. Then increase the flow in your tank by DOUBLE minimum.

 

[ReefFrenzy]

PIMPALA,

I have a Mag9 as a return pump and a pair of Koralia 1450 power heads up top. The Line Loc returns are agitating the surface very well and the tank has been up and running for a year with not a sign of Cyano or any Algae. It only has a few fish as a FOWLR tank. I have the drain and return rate balanced perfectly so the system runs silent and there is plenty of flow as evidenced by the food getting spread through the tank and the fish "playing" in the currents as well. I would suspect if I was lacking in flow I would have pockets of detritus or cyano starting to form, but my sand stays pure white, even without a clean up crew.

Some shots of the 180: