Easy DIY Ca reactor

[mogurnda]

I posted this over on RC at first, to get a little feedback, and it's ready for WAMAS to tear apart.

 

Some time last year, we tried to get some people together here in MD to build Ca reactors. Well, we started the process, looked over DIY plans, and ultimately got hung up because most of the designs required fancy-pants table saws and routers and things. Between that and trying to fit it all into travel and work schedules, it didn't happen.

 

Time passed, and I realized I had built a fluidized bed filter with nothing more than a hack saw, power drill and a few other simple tools. How much harder would a two-chamber reactor be? The answer is that it's not that tough if you want something that has modest output.

 

Here's the basic idea. The left panel shows the thing in operation (ignore the right panel for the moment).

 

 

I can post a schematic with more details about dimensions and fittings if people are interested.

 

There are two chambers, with water flowing from bottom to top. Tank water (from a little dosing pump) and CO2 enter a venturi that goes into a mag3 pump, which pumps the now acidified SW directly into the first stage to dissolve the aragonite media.

 

The SW leaves the top of the first stage and goes to the bottom of the second stage, where it continues the process.

 

Effluent leaves the reactor from the top of the second stage, hopefully full of calcium and carbonate freshly dissolved from the media. In principle the perfect balance to provide Ca and alkalinity for the corals.

 

So how is it built?

 

Simple. Here are the pieces before assembly (and my dog's toes):

 

Just cut appropriate lengths of clear PVC (I had some 3" stuff lying around), use some 3" threaded adaptors and end caps for the tops, and 3" X 1 1/2" adaptors plus bushings for the bottoms. I can provide a full parts list if anyone's interested.

 

For the outputs at the top, I just drilled the caps and put in some 1/2" slipXFPT connectors:

For the effluent output of the second stage, I drilled and tapped for a 1/4" john guest fitting:

 

Here's a detailed view of the "venturi," basically a 1/2" sch80 tee, with one extra hole drilled so the thing can accommodate two john guest speed fittings. One carries CO2, one is the feed from the little dosing pump.

 

Then I glued it all together, connected it all up with hoses, and used 3" pipe clamps to hold it to the inside of the stand:

 

You need something to keep the medium from leaking out the bottom of the chamber. I just bought some foam used for filters and cut it to fit. Works great.

 

Here it is, in the stand, with CO2 tank and pH controller:

 

Here's a better view of the venturi, showing that I added JG fittings with valves so I can remove the CO2 and feed pump tubes without making a mess:

 

A note regarding filling and closing: the threaded end cap system is easy to build, but they have to be totally free of grit when you assemble them, or the grit will shred the teflon tape and the chambers will leak.

 

To prime it, I added a valve after the second stage (see cartoon above, right panel). In normal use, the input to the pump comes from the second stage. When priming, I connect a hose from the sump to the other input of the valve. The pump then pumps tank water into the unit, and air (then water) goes out the effluent port.

 

After a month or so, the Ca is steady at 400 ppm, and the alkalinity is at 4.1. I will try to push the Ca up a little more with more CO2, but it's pretty good, and I am seeing great coral growth.

 

Total cost (assuming you buy all the parts new) ~160.00 with Mag3 and dosing pump, but without CO2 setup. About 425.00 with everything. The learning process was priceless, though.

[mogurnda]

Looks like the old host is finally dead, and I will have to track down the photos. Stay tuned.

[dmatt56]

Dave,

 

Has there been any previous interest for a Kalk Stirrer group build?

 

Matt

[mogurnda]

I think there was a VA stirrer group build several years ago. If Flowerseller doesn't chime in, you might PM him to see if my memory is correct.

[Origami]

I think there was a VA stirrer group build several years ago. If Flowerseller doesn't chime in, you might PM him to see if my memory is correct.

I'm sure that you're right about this, David, as I recall somebody selling one of the units (a year ago) from the WAMAS DIY build. It was a Nilsen reactor design if I recall, using an externally mounted pump to recirculate the effluent.

[flowerseller]

Scan throught the DIY threads. The group builds I led had 5-8 thousand hits and should be easy to find if you look hard enough. It may have been in 05

[Coral Hind]

Scan throught the DIY threads. The group builds I led had 5-8 thousand hits and should be easy to find if you look hard enough. It may have been in 05

 

It seems it was in late 2004 but the links for the post do not seem to be working and I couldn't find it anywhere.

 

http://www.wamas.org...dpost__p__19920

http://www.wamas.org...dpost__p__19676

Edited March 14, 2010 by Coral Hind