Zapping Mojanos

[robbous]

I need one of these so bad I bet I have at least 500 or more mojanos in my tank these things multiply like crazy!!! I have tried joes juice and it kills them but they just come back in a cpl days


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[olliefb]

+1 on the DIY step by step instructions....

 

[ming]

This actually seems easy to build.
I have a spare 12V 300mA adapter, do you think the 12V is enough?
Where did you get the graphite and stainless steel needles? I could probably put them in ridged tubing to get the needle/graphite down in the water, but I'd have to figure out how to completely seal it water proof.

 

[SevTT]

The electrode is emitting chlorine, big time. I found a cheap way to make Clorox.
I tried it for a minute in a small volume of water and smelled it, it almost burned my nose off. This is the substance that is oxidizing the mojanos.
I replaced one of the stainless stel electrides with carbon because the stainless steel on the side that does not produce the gas corrodes very fast. The carbon seems to last forever.

There ya go. That's probably optimal; the electrode that's -not- dissolving is the one that's getting plated with metals, so you don't have to worry about it. (Of course, since most of these are alkali metals or alkaline earth metals, they rapidly oxidize again.)

Keep in mind that chlorine gas is much less stable than Clorox, and I think converts rapidly to HCl - hydrochloric acid - in solution. So, yeah, you're basically hitting them with acid on-demand.

For those wondering: ironically, Chlorine gas is much more toxic than sodium hypochlorite (bleach,) but when it dissolves in water it turns into a much, much less toxic chloride ion -- you get the same stuff when you add salt to water. So with this device you get a very small zone-o-death around the electrodes but don't have to worry about it killing anything else, really. Plus, the amount of chloride ion that the process takes out of the water is pretty much equal to the amount that's going back in (less, actually, since some will probably be lost as gas to the atmosphere.)

 

[Paul B]

Ming, the needle is a sewing needle, the wire is easy to solder to it. The graphite is from a carpenters pencil available in any hardware store, just shave off the wood. You can buy just the pencil lead but that is harder to find. You seal the thing with Goop glue also available everywhere.

I just sent it to Daisy to use.

 

[coralnut99]

Just wanted to say this is one of the most awesome DIY threads I've ever come across. Big old tip of the hat to Paul!

 

[tomtoothdoc]

awesome build paul. now all you have to do is make a detachable extension for it. i have one majano near the very bottom of a 27" depth tank. i haven't been able to reach to kill this thing. it's been bothering me for months now. the only good thing is it hasn't multiply.....ooopppps now that i just jinxed myself....lol.

 

[Paul B]

now all you have to do is make a detachable extension for it

The thing is 24" long and it can all be submerged, even the wiring can be submerged so it will reack about 3' deep. The top of the tube is sealed. They can be made as long as needed but them the shallow mojanos would be hard to reach. One of my models has a plug on the wire going to the tube so a longer or shorter probe could be attached.

I have the two of them lent out and I don't have a spare but I have enough materials to build a few more if I get some time, which I don't think will happen soon

 

[tomtoothdoc]

The thing is 24" long and it can all be submerged, even the wiring can be submerged so it will reack about 3' deep. The top of the tube is sealed. They can be made as long as needed but them the shallow mojanos would be hard to reach. One of my models has a plug on the wire going to the tube so a longer or shorter probe could be attached.

I have the two of them lent out and I don't have a spare but I have enough materials to build a few more if I get some time, which I don't think will happen soon

if it's ok with you i would like to get in line to borrow the ones that are lent out. one of my offices is in flushing so i can pick up from ming once he's done.
i know you mentioned that you are not selling them. so if you happen to feel like making another one, i'll trade for it.....fish, coral, equipment, dental work.....lol. plmk.
thanks, tom

 

[Paul B]

I will let you know when I get one back. If I forget, remind me

 

[ming]

I built my own using a 12V .3A transformer. I actually tried using 2 needles at first but you're correct, the one not fizzing pretty much rusts instantly while turned on and you can actually see the yellow coloration coming off into the water. (tested in a container)
I got a piece of graphite and used that instead, very small bits of graphite comes off and floats to the surface while turned on, which it seems harmless enough, at least no rust seems to be forming and color of the water is still clear.
I tested on three red mushrooms and they become partially discolored really fast. I stuck the needle in each for about 10 seconds, multiple stabs each since I was trying to stab into the center. They're currently slowly shriveling now. I'm anxious to see if they totally die on their own from here.
My plan is to only kill them from the rocks there's only a few of them on. Theres a couple rocks they're totally infested with mushrooms which I won't bother since I'm afraid of the effects of lots of mushrooms dying and releasing toxins. I'll do some every few days to minimize the chlorine effect in my tank.
Thanks for the white-up Paul!

 

[Paul B]

I have 4 more zappers almost finished. (a LFS near my home wants to sell some)
I May build another 10 of them if I get time next week.

I still have not received any back yet of the two I lent out but if I do soon you can pick it up, I am 10 minutes from Flushing (I grew up there)

 

[Arati]

I wanna try this on my wife, she doesnt cook. Im thinking 1-2 pokes with this bad boy and she whips out a sammich for sure!!

Cool stuff Paul!

 

[tomtoothdoc]

I wanna try this on my wife, she doesnt cook. Im thinking 1-2 pokes with this bad boy and she whips out a sammich for sure!!

Cool stuff Paul!

hmmmm....i hope i don't see a headline in the paper..

"man found dead with some home made electrical device making zapping sound protruding from his rear end.....wife told reporters she doesn't know what happened"...lol:biggrin:

 

[Paul B]

This is the completed Zappers

 

[ming]

Looks so much more cleaner then mine.. :lol2:

 

[tomtoothdoc]

This is the completed Zappers

wow...that looks very clean....you're a great tinkerer/inventor/diy'er.:idea:
i would be happy to own one of the original paul b. zapper very soon.....would you sigh it too?....lol.

 

[Paul B]

Looks so much more cleaner then mine.. :lol2:

I'm a clean kind of guy.

They even have a light in the end for those dark places. :scratch:

No, really

 

[Paul B]

I took a video of it working. The mojano becomes a little ball of slime

 

[tomtoothdoc]

cool video....can't wait to get my grubby hand on it...hahhaaha die you majano scum....hahaha:letitallo
i'll remind marcellina to call you.