My DIY Kalk Reactor

[jimroth]

Back when we had the little kalk reactor group buy, I decided to make my own and just buy the valve and the aqualifter, so here goes. As might be expected, costs quickly get out of control, but so far so good! Parts:

• Magnetic Stirrer, EBay, $65, the kind that holds a lab support rod in the back is best.
• Stir Bars, EBay, $11, set of 5 sizes
• 4.5" Acrylic Tube, 24" long, Aquatic Eco, $28. Was actually way cheaper than clear PVC. Extruded.
• 4" Toilet Flange with knockout debris cover (no hole in bottom) Sioux Chief Brand, $6 Home Depot
• 4" Toilet Flange Raiser, Sioux Chief Brand $5 HD
• 4" PVC Slip to Threaded adaptor $3 HD
• 4" PVC Threaded Plug $6 HD
• Qty 2 1/4" slip threaded adaptors to connect the water tubing, $5, HD
• 1/4" threaded stainless steel rod, 3' long, $6, HD
• 1/4" SS Locknuts, $1.50, HD
• 1/8" Pipe Tap, Shaeffer Supply, $12 (ouch) (1/8" pipe is the size for a 1/4" fitting? Weird.)
• 11/32" Drill Bit, local HW Store, $10

I think that's all.

There were only a couple tricky bits: The flange raiser needs to be filed or ground out a 1/4" to slide over the tube. I used a Dremel with a grinding bit, was not really satisfactory. And I haven't had much experience tapping holes (insert vulgar comment here) so that was tricky. Plus I don't have the right tap-holder so I had to fake it.
Screwing the nuts onto the long rod (insert another vulgar comment here) was tedious.

I'm going to post the pictures I have so far, then add more pics of the finished product later. So far it's assembled and it holds water, stirs etc, but I haven't actually run water through it or added kalk powder.

 

[jimroth]

The Stirrer:

Dry fit with the bottom flange and tube:

The whole deal, before adding the support rod and upper flange:

I'm experimenting with some kind of wear pad so the stir bar doesn't eventually wear though the bottom of the flange. This poly cutting sheet was OK but floated to the top of the water. Maybe a round piece of plexi glued to the bottom? Very hard to get my big hands down that tube.

The hose connections are drilled and tapped right into the square piece at the top of the plug. I want to add some rigid tubing for the outlet, so it draws from the middle of the column, but I need to figure out how to bend it properly.

 

[Phyl]

Since your cap is typically for drains and clean outs, just make sure the unit isn't kept under pressure (solonoid should be before the unit, not after). I'm looking forward to more progress!

 

[jimroth]

You don't think it will seal tight enough? Why? I was going to use teflon tape on it. I've seen those caps used at the bottom of lo-o-o-o-o-ng pipes in sprinker systems.

The top is going to be glued just with silicone so I can more easily adjust or modify it, so it's not really a high pressure device in any case.

The unit may just be gravity fed, in any case.

 

[JohnS_323]

I have NEVER been able to get those drain plugs to seal tightly under pressure - no matter how much tape or pipe dope I've used. My recommendation is to do whatever it takes to prevent it from being under pressure.

 

[Phyl]

A sprinkler line doesn't need to be water tight. ;D

 

[jimroth]

Zoiks, good to know.

 

[jimroth]

A sprinkler line doesn't need to be water tight. ;D

I mean at the bottom of a 4-story 6" main distibution pipe. Those are iron though, and may have a lead collar, probably not reef-safe.

 

[jimroth]

I suppose I can make something combining a 4" slip cap and a male threaded adaptor -- that would seal, no?

 

[RichT]

I saw a thread somewhere were a DIY'er screwed the plug into the adapter leaving it a thread or two loose. He then applied a bead of silicone from the inside so that after the silicone sets up, he could tighten the cap against the silicone to create a seal. Of course, you'd have to do this before attaching the cap to the unit. I haven't done this myself so I can't verify whether or not it works. But it makes sense.

I also think he used wax paper or something to keep the silicone from sticking to the plug while the silicone cured.

 

[jimroth]

I saw a thread somewhere were a DIY'er screwed the plug into the adapter leaving it a thread or two loose. He then applied a bead of silicone from the inside so that after the silicone sets up, he could tighten the cap against the silicone to create a seal. Of course, you'd have to do this before attaching the cap to the unit. I haven't done this myself so I can't verify whether or not it works. But it makes sense.

I also think he used wax paper or something to keep the silicone from sticking to the plug while the silicone cured.

I can do that. Thanks!

My plan calls for the solenoids and pump to be up on top of my water tower anyway, so there's going to be no pressure-y pressure, ie, all pressure should be relleved by the output hole. But, like all walruses, I like a tight seal, and I don't want fresh, tasty kalkwasser to leak from the vessel onto my stirrer or workbench!

I now have the taps, maybe I should just go ahead and try to fabricate one of those jobbies with the thumbscrews and keyhole flange. I wonder where one gets those screws?

 

[RichT]

McMaster Carr.

 

[stcreef]

You can bend plastic tubing by first filling the tubing with sand, then heat it up with a hair dryer for the small stuff or a propane torch for thicker tubing. The sand will prevent it from crimping at the bend.

 

[jimroth]

Correction to the supplies list, that's 4 1/2" Acrylic Tube, not 4", don't want someone to order the wrong thing. Admin pleeze correct if possible.

 

[JohnS_323]

Correction to the supplies list, that's 4 1/2" Acrylic Tube, not 4", don't want someone to order the wrong thing. Admin pleeze correct if possible.

Got it for ya, Jim.

 

[jimroth]

You can bend plastic tubing by first filling the tubing with sand, then heat it up with a hair dryer for the small stuff or a propane torch for thicker tubing. The sand will prevent it from crimping at the bend.

Thanks, I'll give it a try. I just bought a heat gun for bending plexi, that should work. Didn't know about the sand.

I added a 3" circle of plexi glued to the bottom of the chamber with a bit of silicone. It's smaller than the tube so I can (hopefully) pry it off when/if it needs replacing. As an unexpected plus, the stirrer spins more smoothly on the plexi than on the flange bottom.

Did the silicone sealer thing Rich T. mentioned, used saran wrap around the cap and it pulled away nicely from the silicone, leaving a kind of custom gasket.

 

[paintballe48]

how do u plan to attack the input and output?

 

[jimroth]

I got some connectors at HD that are threaded on one side and RO Tubing push-ins on the other. Then I drilled and tapped the holes into the square part of the plug and threaded them in with teflon tape.

Alternatively, I could have just drilled holes and stuck RO tubing through them, and sealed around the tubing with silicone. Probably should have, Except for the convenience of taking off the tubing when removing the cap to add kalk powder.

 

[jimroth]

Successful test run yesterday.
As predicted, it was very difficult to get the top to seal. I really had to dog it down tight with a wrench. That's going to make recharging it very inconvenient. I thought thumbscrews were bad.
Other design issue is that because the wear pad does not cover the whole floor, it is possible for the stir bar to become jammed between the vessel and the wear pad. Not a deal breaker but again, inconvenient. Happens if you turn the stirrer up to maximum.
Still, it worked as planned and air pressure pushed the water up the tube to the outlet.
Since I am siphon feeding it from a 50G barrel which is 4' off the floor, I feel the need to slow down the flow somewhat. HD sells a little 1/4" ball valve by Watts. The other issue is, of course, the possibility of feeding all 50G of water into my tank. I have one solenoid to control the flow, I think I may add another. It would be good if there was a way to detect a single failed solenoid...

 

[RichT]

did you use the silicon bead around the inside of the coupling?