Building a Large, Modular Calcium Reactor

Sisterlimonpot · Jun 3, 2019

The acrylic tube is what makes it so expensive. Things have gotten so expensive these days. Same with the nylon screws, 10 years ago they were a dime a dozen, the cheapest I can find 1/4"-20 black nylon screws that are 1.5" is on amazon for $18. It's like playing the stock market.

10 years ago I bought a bunch of john guest fittings for pennies each, these days the stock is higher... hehe.

Sisterlimonpot · Jun 3, 2019

ca1ore said:
Acrylic tubes were 75% of that - the rest not too bad.

There's a place locally that has a surplus of acrylic tubing that they are slowly getting rid of. I just bought 12' of 8" tube for $200, and 12' of 6" for $150 locally. I don't have plans for it yet, but I couldn't pass up the deal...

ca1ore · Jun 3, 2019

Yes, that is a good deal indeed. How will you cut it to length though? I don’t have a good way in my shop to cut large diameter tubing so that the ends are perfectly square. I guess I could have setup a jig on my table saw.

Sisterlimonpot · Jun 4, 2019

Yep, a jig on a table saw and an autographed nozzle to keep the acrylic from melting.

Sisterlimonpot · Jun 4, 2019

Yep, a jig on a table saw and an autographed nozzle to keep the acrylic from melting.

Water Dog · Jul 3, 2019

When you screw in the John Guest fittings into the holes with the threads tapped into your lids, do you shave off the extra threaded part of the fitting that extends beyond the lid to make it flush with the underside of the lid? If so what do you use to shave the threaded part to make the fitting flush?

I’m thinking about tapping some threads into the lid of my GEO CaRx so I can attach a John Guest elbow in order to move the “effluent out” line from the recirculation loop to the lid, thereby alleviating gas build up on the lid when using a peristaltic pump in the pull configuration.

Sisterlimonpot · Jul 3, 2019

Sisterlimonpot said:
Yep, a jig on a table saw and an autographed nozzle to keep the acrylic from melting.

Wow! how did auto correct change "air" to "autographed"?

ca1ore · Aug 12, 2019

It’s taken me some time to get this thing dialed in. My 15 year old regulator had started acting strangely so I bought the carbon doser as a replacement. I think I got my money’s worth out of the Milwaukee unit tho. I have a trident, but I use it to monitor alk/CA only. Goal has been to set the CaRx so that it maintains nominally an alk at 9 dkh.

Anchor · Sep 1, 2019

To cut acrylic tube I set up a plywood "V" over my router on a home made router table and then slid the tube over the bit and rotated.. with a cap on one end of the "V" to hold the tube in place (read as push against). has worked wonders for cutting tube.. Sure beat doing it on the table saw... Much too rough a cut on that saw. Making my own skimmer.. Might have to do a CaRx after reading this.. Excellent work!

Anchor · Sep 4, 2019

@ca1ore I have a question about your gasket material. Did you get this on Amazon too? Is it silicon or standard rubber sheet?

ca1ore · Sep 4, 2019

Anchor said:
@ca1ore I have a question about your gasket material. Did you get this on Amazon too? Is it silicon or standard rubber sheet?

Yes, silicone sheet. Rubber Sheet Warehouse on Amazon.

ca1ore · Jan 30, 2020

Anchor said:
To cut acrylic tube I set up a plywood "V" over my router on a home made router table and then slid the tube over the bit and rotated.. with a cap on one end of the "V" to hold the tube in place (read as push against). has worked wonders for cutting tube.. Sure beat doing it on the table saw... Much too rough a cut on that saw. Making my own skimmer.. Might have to do a CaRx after reading this.. Excellent work!

Coming back around on this because I want to cut some tube. Any chance you have a picture of the sled? Or is it as a simple as it sounds LOL? What bit did you use - upcut spiral? Thanks.

Anchor · Jan 30, 2020

No photos, sorry, and yes it is just that simple.. so long as you have a good "V" and can hold the tube in place as you turn it. I actually used a 1/4 inch straight cut bit but like the idea of the spiral bit is better. May have to invest in one if I cut more tubing.. which is in my future. If you put a stop on your router table so nothing slides laterally, you should be good.

Anchor · Jan 30, 2020

I will go look in my garage and see if I can find the V sled, Wasn't much of a sled as it was a fixed position one once clamped in place. I lowered the tube onto the bit and rotated. Perfect length positioning. Does this help?

Also, if you don't have a table, you can make a jig to hold the router upside down out of a piece of quarter inch acrylic or polycarbonate. Then drop it into a cutout in a 3/4 inch piece of plywood so as to make a fixed table.. I use this for a few years before I made my table. clamps become your friend then.. SLow to set up but always consistant.

DeniseAndy · Nov 29, 2020

Great design. I am going to modify my Ca Rx too. I also have the old style HSA skimmer, but such a beast, I love it. Well made stuff stands the test of time.