Hi Andy,
Thanks.
I had fun with this design. I want to see if the same theories about water stability in larger tanks will apply in this case. What I am hoping(and seeing so far) is that once you get your Rx to the desired levels it will remain there for the most part. Here is my reasoning behind this.
With the larger volume of H2O in the Reactor(Rx), as you add the 100ml/min of water from your tank you are only changing a much smaller portion of the Rx's total volume. There is two gallons(~8 litres) of H2O in this design. Where my old one had maybe 1/2 Gal(~2 litres). So four times the volume. Adding & expelling 100ml/min means the entire Rx theoretically empties in ~80 minutes( I know it takes longer due to fluid dynamics, this is just in theory). Where in the smaller reactor it will take only 20 min. With this high turnover in volume it takes a lot more CO2 to get all this new 8.3pH water down to about 6.5. Once again. theoretically about 4x's.
So by having the extra H2O you are looking at a reduction in CO2 use. Once you get it down to the desired settings that is. To get it there you will need to put a bit extra CO2 in. but once it's where you want, it should be stable. When I introduce that 100ml/min of fresh tank water I am forcing out only 1.25% of the total volume where in a smaller Rx 5% is changed. Meaning more CO2 is needed to get that new water down in pH in the smaller Rx than the larger. Large vs small tanks hold the same principles. If you were to add 50 ml of B-ionic to a 20 gallon tank you can see a much larger change than sayif you add that same 50 ml to a 120gallon tank.
The recirc idea is one that playfair on RC posted about. It seems to work quite well. If I get a CO2 build up in the Rx, it is fed back into the circulation pump with water and is chopped up and sent back into the main reaction chamber. Playfair has dropped his CO2 use down to 30BPM. And as the day goes on since turning this thing on I am slowly dropping mine down as well. I was at 60BPM to get it down to 6.8 but at this moment am running about 40-45BPM. And all is well(fingers crossed).
One thing I really like about the 24" height is that the CO2 rich water has to pass through a lot of media to get to the pump. All this contact time should result in a more efficient Rx. I hope. lol. Once again my theories are in effect here. Instead of passing the water through 12" of media right now my water is having to go through about 17-18" of media. Hopefully reasulting in a lower number of times a ml ofwater needs to pass through the Rx to achive the results I want. Higher Ca, Alk and lower pH.
Basically this is all an experiment. I have this Rx on my tank and a similarly designed Rx on a buddies tank. He hasn't ran a Rx before so I can't really use his as an example but can get some general numbers and data fom him. If this works. I'll be happy. If it runs the same. C'est la vie. I am still happy. I have a Rx that holds enough ARM to last a year.
lol
[ March 28, 2002: Message edited by: DJ88 ]</p>
