Inefficient Ext Reactor.

[PeterGwee]

Just to add on to what Vinz has mentioned, consider checking the CO2 line connections for leakage. Those type of setup you had has considerable amount of back-pressure exerted on the CO2 line and will leak if not secured properly. (that is the reason why I followed Tom's methods on his CO2 reactor running style....feeding into powerheads and outputing it into external units or direct feeding into an open-end tube like the internal unit w/venturi action. No back-pressure at all and the less tendency to leak.)

If the tank is not pearling at all, you can be sure those air-gaps in the reactor are not reallly O2.

Regards
Peter Gwee

[cherabin]

Ok, I'm jumping into this thread late...

I'm using NA custom built external CO2 reactor on a 6'x2'x2' tank. Even when my tank had a large volume of plants which were producing O2 abundantly throughout the day, I've never had more then 10% of the reactor filled with gas.

Let me state upfront, I'm not disputing Tom and Peter about the degassing of O2 into the reactor chamber. But I don't think 80% to 50% of your reactor filled with gas is due (completely) to O2 degassing. Your bps is too high.

I don't think I've ever gone above 3 bps for this tank. So, I don't think you need 10bps. 2 to 4 bps as suggested by Peter should be good enough.

Come to think of it, how did you get 10bps? IME, bps that high becomes a continuous stream that is impossible to count. Are you sure you counted correctly? How do you count your bps?

During the time my tank was in the above condition, it was running on a filter with a output of 1000 l/hr, so your 2226 with 950l/hr should be efficient enough for this reactor.

I think your problem is more with circulation. Do you notice the BBA growing only in certain parts of the tank and not others?

I've had BBA problems with this tank before, but due to poor circulation. re-directing or re-positioning the spraybars solved my BBA problems.

How are you positioning your spray bars?

Check your filtration loop for flow obstruction.
1. Are your hoses clean?
2. When was the last time you cleaned the filter media? Especially the fine wool?
3. Don't over-pack the fine wool... it will slow down the flowrate. Make sure the topmost tray is not filled to the brim and has space for the fine wool... it will compact the fine wool and make it harder for water to flow thru.
4. When was the last time you clean the filter impeller and housing. Including the inlet and outlet valves?
5. Check the hoses for kinks.
6. Make sure the hoses are not overly long. (Try to make sure the hoses do not dip too low.)
7. Check the positioning of the hose in the middle of the external reactor. If you have removed it for cleaning before, the hose might not be position properly. If that hose drops too low into the hole, it blocks water flow. You may need to modify it. See the attached picture. It shows the base of the reactor. In the modification, I cut the end of the hose diagonally and make sure the open side faces the water inlet.

Consider splitting your filter inlet into two and positioning the inlets at different ends of the tank.

Spraybar is located at the bottom side of the tank, along side the filter inlet.

1) Hoses are clean.
2) Just cleaned last month.
3) Only used a single layer of soft white wool above the trays.
4) That would be quite sometime ago
5) No kinks in hoses as they are kept short and tidy.
6) As mentioned, the hoses are short.
7) Never open up the ext reactor before.

Was actually considering splitting my filter outlet into 2 for better circulation. Which would be a better option, splitting the in or out?

Many thanks for yuor advice.