CO2 reactor

[Karen03]

Hello again.
Last night I switched out my CO2Art diffuser for a previously owned Aqua Medic 1000 reactor. I have a 125g tank with pressurized CO2 using CO2Art regulator. The experience so far with the reactor is not what I was expecting. I have had to put my bubble count way up to achieve decent CO2 levels.

Here's the background:
I felt I had maxed out the diffuser and was not quite getting the CO2 levels that I wanted. Almost, but not quite. The drop checker would turn green, but only just green, never close to yellow. My pH drop was not quite as big as I was hoping for. The needle valve was at 4bps. I could not get it to get faster than that -- my guess was that the diffuser was limiting it to 4bps.

Today has been day 1 with the reactor. I have it hooked up to the outflow. I think all the CO2 is dissolving. I don't see any bubbles in the outflow.

Because I thought the reactor would be more efficient than the diffuser, I started at 2bps. Drop checker stubbornly stayed blue, pH hardly budged. I kept increasing bps throughout the day. 4 bps was too low, 5 bps was too low. Ended up with a constant stream of bubbles. I cannot count faster than 5bps. By this afternoon, just before the solenoid switches off, I had managed to achieve CO2 levels similar to what the diffuser achieved.

Something doesn't feel right to me. Someone has suggested to me that the amount of CO2 in the bubbles is different in the lower pressure reactor system than in the high pressure diffuser system. Does that make sense?

I've done a leak check and cannot see leaks. I see lots of CO2 getting into the reactor. I'm tempted to go back to my diffuser.

Does anyone have any advice for me?
Thanks in advance!
Karen

More info on the diffuser and reactor:
CO2Art diffuser (https://www.co2art.eu/collections/aquarium-diffusers/products/new-in-tank-bazooka-flux_-co2-diffuser-for-planted-aquariums?variant=14432414400554)
Aqua Medic 1000 reactor (https://aquamedicdirect.co.uk/product/water-quality/water-quality-co2-ozone/co2-reactor-1000/)

[lucius]

What type of canister filter are you using. Maybe you don't have enough flow?

[Karen03]

Good point. The reactor is on a Sicce Whale 500, which has a stated flow rate of 1300 l/h. The Aqua Medic says it needs a flow rate of 1000-2500 l/h.
I don't think I understand well enough how the reactor is working. Wouldn't a lower flow rate give the CO2 more time to dissolve?

[lucius]

I was actually thinking that maybe the canister filter is not strong enough to push all the CO2/water from one side of the tank to the other.

[Karen03]

Thank you Lucius. I have just moved the drop checker to same end as the Whale outflow (CO2 outflow). I'll see if the drop checker gives different readings from different ends of the tank.

I have two canisters (Whale 500 and Eheim 2217). The outflows are on the short ends of the tank, each flowing the water towards the middle of the tank. The drop checker was on the opposite side from the Whale/CO2 outflow.

The tank appears to have good flow, but I'm not very experienced in these things. The plants gently sway. Food moves around in currents at feeding time.

When I check the pH, I usually take two readings -- one from each side of the tank. They are always the same.

Today I've bumped up the bps even more. Too fast to count bubbles -- it's a stream of bubbles. I worry I'm going to empty my CO2 canister quickly. But then again, this is a much, much lower pressure system than with the diffuser. A smart in-house consultant (i.e. a family member) has told me that the density of the CO2 inside the bubbles is much lower in my new setup, as the bubbles are not being compressed the same way. He tells me that I am not necessarily using more CO2 even though my bubble rate has more than tripled. I have read supporting opinions on some forums.

[exv152]

I'll be honest, I been running a high tech planted 125g for awhile on a DIY reactor. The reactor is 2.5" wide x 24" long, made of PVC pipe, and i ditched my bubble counter a long time ago and went with a pH controller. I aim for a 0.85 pH drop. But I have to add lots of flow to the tank (3x canister filters) plus a 1200 l/h powerhead, and I still get some dead spots because of the dimensions of the tank. My 10lbs co2 tank  lasts about 3.5 months before needing refill. Doing a 125g high tech tank is fairly challenging. Let us know what the outcome of your co2 situation was.

[Karen03]

Thank you for this! 

How do you determine where you have dead zones? I was considering changing the drop checker's location every few days, but I suspect you have a simpler method.

It is very helpful to learn how much CO2 you are going through. I'm still in the mindset that my 10lb tank should last about a year. I see I'll need to reset my benchmark. I would have thought something was wrong without your experience. Thank you!!

[exv152]

You might have better success with an inline atomic co2 diffuser connected to the output of the sicce 500 which has more flow (390 gph). It also wouldn't hurt to increase the overall flow rate in your tank with the addition of perhaps a powerhead.