Bored..... So....

[DJ88]

Tony and I have basically the exact same copy of your old reactor design with a recirc line.
Mine runs at 30ml/min (not drops) and I am using 90 bpm of co2 and I am getting a ph of 6.7 in the reactor. I realize I cant compare my results to your new design but I mainly speak of the results/rates of your old one.

From the pictures that were put up online and the final reactor I was running to get the results i was getting with my old style reactor I made lots of Modifications. Mainly to do with the efficiency of how the water, recirc line and CO2 were pulled/brought into the recirc pump. The design you have followed(main body and design of reactor) is pretty much the same but I did a few changes as I wasn't getting near the numbers I wanted or expected. At first I had to run about 80 BPM plus and 120 ml/min to get down to 6.9 and dKh of ~20 where I prefer to run ARM. I just fiddled with how the recirc line(where it is injected) was introduced and found that if I created a small venturi it ran much more efficiently. It was hours upon hours of fiddling and trying ideas. I made a real mess of that reactor. It worked fine but it was a big test piece. That was when I realised where reactors of a single pass design are inefficient and I came up with this new idea. A few parts of my new design actually. If that reactor would keep up thise rates I cant say. But for the last wile when it was going I was running around 60BPM and 120 ml/min with my fav numbers for pH and dKh.

One thing I did want to mention is that when it comes to BPM is that numbers will be different from reactor to reactor unless the bubble counters are 100% identical. and I mean 100%. With the new design bubble counter I am using I am using poly line inside the counter where on my older ones I had used a small piece of hard plastic line. And I know the ID of these lines are different(not a lot but enough that I think there is about a 25% increase in bubble size, maybe?). This will account for smaller or larger volume bubble sizes and higher or lower bubble rates.. This coudl account for a huch higher required bubble rate on your part is that your counter has such a small restriction that the bubbles are MUCH smaller in volume than what I run. The only way to compare BPM IMO is to sit down with some form of a flow meter and physically measure the actual amount of CO2 being introduced into the reactor. So I will add in. Please take my numbers as what I am getting for my particular design of reactor and counter. Use the numbers I get as a rough guide to base yours on. I can't see how your reactors are set up, hooked up and are running so I can only speculate what is accounting for differences. But there could be many as there are many parts to a complete reactor.

I will say that if you aren't using lines that can handle gas under slight pressure or is porus in any way you may have problems. ie leakage of CO2. incorrect seals. brittleness may cause problems such as small cracks or weakpoints. If you are having difficulties getting a stable bubble rate that is a prime indicator of a leak somewhere. IME. And it is just that.. my expereince. Short of tossing your reactor on the plane with Deb and getting her to courier it here wher I can fiddle with it.. I can't say.

Another thing to keep in mind is that in my post listing CA reactor rates I am talking about three reactors. This new one. my beast and a smaller one I had prior to this.

Another thing that with this one I will say WILL change is that when I bump the effluent rate up to where I usually run them(120ml/min) I know that my demand for CO2 will rise. Most likely up near 30BPM. I am guessing.

do you have to use the ARM media or can you use crushed coral? Is there a huge difference

I use ARM as it doesn't require as low a pH to dissolve. You can pretty much use any Calcium based material inside there. Crushed coral will work but may take more CO2 to drop the pH down. One thing that MAY be a problem with ARM is that it releases phosphates. Some people are saying that when they used ARM they had algae problems. I can't say for sure. The main difference is price for one. $25 for a gallon of ARM. Crushed coral is cheap. Another difference is that less CO2 is needed to drop the pH as far with ARM.

I highly doubt that there is different grades of CO2. CO2 is CO2 me thinks. I bought it at AIRLIQUIDE. If that helps.

I use poly tubing. And will be swapping mine over to a opaque shortly so that I dont' get growths inside.