Loaches Online Forum

Induced voltage is perfectly safe, as the fish (and your hand) aren't actually being exposed to it. Here's how I can explain it best: Imagine a coil of wire with 120v of alternating current running through it. Now take an identical coil hooked up to a meter and bring it close to the first coil. Your meter would read 120vac (or near that). However, you could put your hand in between those two coils and feel nothing, because the coils are magnetically coupled as opposed to being directly connected to each other.
In your tank, the jet heads are acting like the first (primary) coil and the meter lead is acting like the second (secondary) coil. The medium in between (the water and fish), feels nothing. You can also relate it to a radio receiving signals from an antenna, though it's not quite the same thing.

Your heater is a different story. Imagine taking a piece of copper wire, sticking one end in the hot side of the power outlet and the other end into your tank. This may be an exaggeration (depending on the level of insulation breakdown and where in the circuit it is exposed to the water), but it gives you the right idea. That is a direct connection. Anything that comes in between it and an electrical ground will feel a jolt (or worse).

Why your poor fish is still clamping, I don't know. Hopefully, he just needs some time to recover and will be fine.

Diana wrote:As an alternative power head look into the Koralia product line. More water movement for less electricity.
More difficult to add any sort of filtering sponge, though.

And it is recommended to have some sort of cage on it.... I lost a dwarf chain loach (sid) on the weekend. It was amongst a dozen or more loaches that were racing excitedly around the tank after a large water change. Right in front of my eyes they were playing in the flow from the wavemaker powerhead. This extra quick sid swum extra hard and got straight inside the cage of the powerhead.... it got bounced around a few times in the cage and then was spat out by the water flow. Unfortunately it sustained two wounds on either side near its gills, and died a few hours later.

The power head is now off until I can work out a way to enclose it better in a loach proof way (damn guys are always soooo inquisitive and adventurous and will try any little opening).

Matt

My tank voltage is 11.4 with only 2 rena x3 fillstars attached. I will take another reading once I put the jethead back in. Right now I have aquaclears with the filter attachment. I used to run the river tank setup but as the loaches are getting bigger I find the pvc piping a little intrusive to their space.

Ok so after a few more months the striata in question looks back to normal. I am pretty sure it wasn't stray voltage now. The striata was still having the issues after everything was removed from the tank. Everything is back in now and there are no issues. Must have been some bullying or something going on I can't account for.

Koralias do indeed present some danger to the fish. There are already posts here (I think) about how to wrap them with a coarse, stiff net and secure it so the material cannot get into the impeller.
Another option is to use the Koralia as part of a Hamburg Mattenfilter. There is a lot of info about this style of filter elsewhere, here is one link.
http://www.plantedtank.net/forums/showt ... ttenfilter

There is more info here at Loaches about a similar use for this style of power head.

Its been 7 months since my last post. I tried everything listed in this thread. I have completely removed the heater element and the fish still had issues over 6 months after. Nothing worked. Come to find out it must have been the other fish picking at the runt. All of the sudden recently in the last few weeks he stopped clamping his fins. I had added another smaller striata and I believe they are both sharing the lickings.

Thanks for all your help everyone. Conclusion: NOT STRAY VOLTAGE.

check the DC voltage once also-if you have the plant weights-they are lead I believe, and something acidic in the tank could cause a battery effect-more just interested to see what it reads really-it probly wouldn't cause enough amps to shock you or the fish though. if there is something acidic also that would cause a sting and possibly cause some discomfort to some fish? Have any of the meds you used have salt, and how salty is it if so?
LoL-I guess I should have looked at the dates of the posts