[Wet Thumb Forum]-CO2 Reactor problem or not?

[rcp]

Hi there

I have an Aquamedic reactor 500 running with around 3bps. Its powered from a powerhead which supplies 375 lph. My aquarium is around 75 gallons.

The issue is that the CO2 seems to build up in the central column of the reactor. Occasionally a bubble will enter the outer spiral and make its way down. My pH is 7 and kh 11 so something is obviously happening as my tapwater ph is around 7.4. I don't use any buffers. No bubbles seem to be leaving the reactor from any other holes.

Can someone tell me if this is normal operation or otherwise?

Many thanks

[John N.]

With 3 bps, I think you should be getting better co2 dissolution, but that doesn't seem to be the case with only a .4 drop in ph.

I haven't used the AM500 myself, but it sounds like a hagen ladder that's driven by a powerhead. Since you don't see any bubbles escaping the reactor, I would expect a high co2 level. Check you test kit, it could have expired, and/or is giving you a false reading.

-John N.

[Hawkeye]

I use to use the same set up some of my small tanks. The only way I could control the CO2 build up was to cut back on the bubble count or increase the flow. BUT there is a point that to much flow will cause low amount of CO2 being dissolved. I never had much luck using the 500 on larger tanks. 20gal was the biggest tank. They just don't work on larger tanks. IF I remember right you can stack two together for larger tanks but if you have to buy another one just get the 1000. Its works fine on my 75gal but make sure you have plenty of flow.

Hawk

[rcp]

ok, thanks for the replies.

I have been thinking about purchasing a 1000 and running it off a dedicated pump. Does anyone know what pump flow rate I should go for - I think the reactor is rated at 250gph. What is the impact of using a higher rated pump, ie if I attached a 350gph pump to the reactor 1000 would it not work properly, does the flow need to be exactly 250gph?

Thanks again

[John N.]

With higher flow rates, you might end up pushing the co2 out of the reaction chamber of the AM1000, thereby reducing co2 dissolution effectiveness. If you can reduce the flow that would be better. You want the co2 bubbles to stay in contact as long as possible inside the AM 1000.

-John N.

[Hawkeye]

I run the 1000 on a dedicated canister filter that has a 250gal/hour and I have had problems with getting it to dissolve CO2. What I had to do was gut the canister to increase flow. Once I did that it has been working fine. As for a dedicated pump I would go for something in the 350gal/hour range to be on the safe side unless I had a smaller one laying around. Then I would give it a try. The problem with the 1000 is that its has a large volume of space to flow thru. I fine that on the reactors I make from 1 1/2 inch PVC works better with lower flow rates. With the PVC I make them longer then the 1000. Don't get me wrong I like the 1000. I use them on my larger tanks but they do need plenty of flow to maintain a constant CO2 level with out getting CO2 build up like you have with the 500.

Hawk

[JERP]

I had the same problem. The Aquamedic requires alot more flow than I was willing to give it. I changed to an external inline DIY reactor.