Yes, the flow comes in from the bottom. I have the dry circulation pump sucking from the top and going into the bottom of the reactor. Also there is a small return pump in the bucket that is pushing the "tank" water into the bottom also. The effluent comes out the top and then back into the bucket.
As for the size of it, I used 3 inch clear pvc. It's is 17.5 inches tall. My display tank is about 120 gallons. According to Parkers Reef on youtube I have 3 cups of sulfur and a little over 1 cup of ARM.
I would add a valve on the incoming line then, to help throttle flow, instead of, or in addition to the valve up top, and test for nitrite. As the reaction becomes detectable it will first begin producing
No2.
Additionally, and take this as you will, with nitrates values
below 50mg/L the recommended volume of sulfur media is 1% of your tanks volume.
With Nitrate values above
50 mg/L the recommended volume of sulfur media is 2% of your tanks volume.
As for your sulfur media, you likely do not have enough; see, at 120g of H20, and being that there is
7.48g of water per
ft3, we can do the meath and show this leaves you with a volume of
~16 ft3. Again, the recommended media ratio being
100:1 or
1% of the tanks volume would work out to be 0.16 ft3 of sulfur media. Since each ft3 has
119 cups per
ft3, the math then works out to be
19 cups of media. you have three?
Determining Media Needs:
1.) Convert gallons to cubic feet:
120g / 7.48 (g/ft3) = 16.04 ft3
2.) Take 1% of your tank v in cubic feet (ft3):
16.04 ft3 * .01 = 0.1604 ft3
3.) Convert cubic feet to cups:
0.1604 ft3 * 119.68(cups/ ft3) = 19.19 cups
The source water's nitrate values running above
50 mg/L would mean you specifically need
2% of your tanks volume, which would put you at 38 cups of media instead (That is a lot.) Implying you were using an imperial cup which would hold ~285 mL.
My advice, if you would like to hear it -I would ditch the calcium and fill it's space with more sulfur and additionally I would recommend building a second tube with straight sulfur and run them jointly and in series. This would also mean lowering
No3 to less than 50mg/L to be successful, and using slooooow flowrates.
Instead of calcium you can aerate the effluent to off gas the Co2 produced by the reaction and this will help with preventing changes in pH.
As you can see from the picture, these things have a tendency to get gigantic in order to function properly.
