Ok, since I promised to show how to build a very simple and inexpensive reactor here is the article.
A - 1.75" PVC T
B - 1.75" PVC T with one 1.5" outlet
C - 1.75" PVC pipe about 18" long
D - 3/4" hose barbs
E - 1.5" PVC plug
F - 1.75 " PVC threaded plug with 3/4" thread
G - Same as F
H - 1.75" PVC cap.
Note I picked up these parts in about five minutes at the local Home Depot.
Both T parts can be straight 1.75" with no problem. If they are then E needs to be 1.75"
If you need 1/2" hose barbs then get parts F and G with 1/2" threads.
Part E is simply drilled with a small drill bit and the CO2 feed line is fed though the hole.
Here is the reactor fitted together. Note I have NOT glued anything together. If someone wants to purchase this reactor then contact me via my web site. I can put any size hose barbs you need within reason.