The Planted Tank Forum banner

RG reactor micro bubbles

3K views 37 replies 7 participants last post by  natemcnutty 
#1 ·
I've built 2 RG style co2 reactors now for my 75. The first one was way too small even after consulting people on here. The second (currently in use) is much bigger. It's made with 2" inner diameter pvc and measures somewhere around 27" in length. I'm using a hydor professional 350 that has been dialed back roughly half way to keep the bubbles to a minimum. I inject co2 at 10 psi with 2bps.

The 2 issues I'm having are I either get gurgling if I turn the flow back even further or to stop the gurgling I get nothing but bubbles if I turn the flow up.

The reactor is as big as I can build to fit under my stand but it still isn't enough.

I've read of putting a valve after the reactor to increase pressure but I feel that will still leave me with the annoying gurgling noise from co2 building up.

Any input or experience would be greatly appreciated, I'd really like to push the co2 a little higher in my tank even though my drop checker is already yellow.
 
#2 ·
Youd be better running the filter wide open and adding a ball valve after the reactor to adjust the flow. This will create better pressure inside the reactor. Simply turning down the flow on the filter does not.

Even a small increase in pressure helps tremendously. It will also cut down on the gurgling because more co2 will be dissolving instead of building up.

Another thing is you can use a shorter pipe with a larger diameter, a 3" dia will handle more CO2/flow than a 2"

There may be other improvements you can make, pics of the rector might help.
 
#3 · (Edited by Moderator)
I went with 2 inch because at the time the hardware store didn't have any end caps for 3 inch pvc, plus the power supply for my light is taking up room making space limited.

I'll take some pics here in just a little bit when I get back home

Here's my reactor, at 1bps at 10 psi and the filter wide open it takes maybe a minute to start producing micro bubbles in my tank along with the gurgling noise.
 

Attachments

#4 ·
How long has the reactor been connected? It can take a day or two to get all the air out when you first hook it up, or anytime after it's been empty.

Is the co2 line connected to a fitting, or going straight into an undersized hole? Looks like a fitting?

The original Griggs design emphasized the undersized hole method, in order for the co2 to enter in the center of the pipe, instead of at the edge. Ive never done mine that way but it could possibly help.

Here's a picture of mine. The main pipe is 24" x 3" diameter. I reduced it to 2" on the ends because I couldnt find any 3" end caps like I wanted either.





It's connected to a Hydor 600 on a 120 gal, too many bps to count, 7-10 if I had to guess.

Note the ball valve on the return line. With that wide open I get tons of mist, and some gurgle, closed maybe 20-25% there's essentially none.
 
#5 ·
The line goes to a brass fitting with another piece of tubing in the end to extend it to the very center of the pipe. And the reactor has been running since mid January. I'm not one to trust a hose pulled through a smaller hole especially if it were to be accidentally pulled on or something.
 
#9 ·
I note that you have the reactor strapped solidly. I might try a simple item before changing things too much. I find I have to tilt my reactor to let the air pass through the water and on up to the tank. Maybe easy to try letting the reactor loose and tilting it so that the air collected at the top will pass on through? I find CO2 will be absorbed/adsorbed easily but not so quick with air.
 
#10 ·
PlantedRich, I did that when I first set the reactor up and then let it run Luke in the pic up until current. Once the co2 is off the gurgling goes away in about 20 minutes on average. I wish I had installed a tube or drilled a hole in the upper cap to keep a bubble from forming but I forgot to. Luckily I made my reactor serviceable with a screw out top.

As of yesterday though I dropped the co2 back to 1bps at 10 psi and I still get just the faintest of bubbles and about half of the gurgling noise, but my drop checker is still a yellowish green color. Once I get some more cash in my pocket I'm going to trytry putting the valve inline after the reactor and see how that does. Hopefully it helps other wise I'll be building a bigger diameter reactor with a lot of changes internally, or I might even switch to a cerges style reactor. But that's as a last resort though.
 
#11 ·
Here's a dumb thought... CO2 will dissolve more slowly as co2 concentrations build in the water. If you're already getting a nice lime green color, maybe trying to get it up to yellow is more difficult. I would just stick to 30ppm and be happy with it to be honest.

Sent from my SM-G920V using Tapatalk
 
#12 ·
Either way, I'm still dealing with the gurgling and micro bubbles. Even at 1bps at 10 psi which is the lowest pressure my regulator is capable of reading. With the NV-55 needle valve it's already only an 1/8 of a turn open at most at that setting. I'm going to try adding the ball valve inline and see if that helps. I have several other canister filters I can use if I end up having to run it on a separate loop all together because of filter efficiency and flow rate.
 
#13 ·
There's NO WAY 1 or 2 bps is getting 30 ppm in a 75 gal tank, unless they're incredibly huge bubbles! :)

5 or 6 bps will be closer to the ballpark.

Forget the drop checker. They're a rough guess what happened a few hours ago...at best, or just wildly inaccurate.

To get an accurate idea you need to measure the PH of degassed tank water (sat out for 24 hours), and tank water with the CO2 on.

Shoot for a full 1 point drop, ideally it should be pretty soon after the lights come on.

Then, once you get the CO2 set, you can note what color the drop checker is, and use it as a quick visual reference to make sure it's the same every day. That's about all a drop checker is good for.
 
#14 ·
Well they are pretty big bubbles going into the reactor, and with it having a pocket of co2 at the top I'm sure I'm only really keeping the reactor fed at this point so it's sort of like I'm running a higher bubble count. I'll pull out my test kit and check everything though seeing as I have some tank water left over from mixing up some fertilizer last night.

Also, I've noticed that my drop checker will change within about 10 minutes of a co2 adjustment. I guess I just got lucky with it?
 
#15 ·
Well it's not really supposed to change that fast. Where is the drop checker positioned, relative to the filter's outflow direction?

If misty CO2 water is being blown on it, or under it, or near it, it's going to show a lot higher than whats really there.

Put it down low somewhere in a lower flow area. See if it still turns yellow.
 
#16 ·
It's on the opposite end of the tank about midway down the side, relatively low flow right there and at my current setting it's more yellowish green. I just replaced the fluid a few days ago when I did a rescape and deep cleaning. There were no instructions with the drop checker kit, purchased on co2supermarket over in the UK.

I could try moving it over to under the output from the filter where it's even lower flow and see how that does.
 
#17 ·
Yeah try moving it to the same side as the filter, down low. Having it on the opposite end is going to read the highest.

Which is not a problem if you're getting 100% dissolution. But with a lot of micro bubbles, they can get in there and pop, causing it to read higher than it really is. That's the main thing you want to avoid.
 
#18 ·
For my 65 gal tank I built couple of Cerges type reactors. The only successful one was one with a 20" housing with a ball valve on the outlet closed about 30%. The back pressure was the key to minimizing micro bubbles and achieving the required pH drop.

I am currently building a 135 gal set up and just finished the CO2 reactor. This time round I opted for a RG type reactor: it is a 3" x 24" pipe with "T" connectors at both ends. The reactor is fed by a Hydor 600 canister filter and there is a valve on the output. With the valve fully open, I do notice some micro bubbles - nothing annoying though. With the valve closed about 20%, absolutely no micro bubbles and a pH drop of 1.0 in about 75 minutes. Bubble count is about 10.. too fast to get an accurate count.

The drop checker, in my opinion, is just a visual indicator for CO2. pH measurements are more accurate indications of CO2 levels.
 
#19 ·
Since I won't be able to get a valve for a while I came up with something to act as a valve in its place, to see if it changes anything.

I have a feeling I'm going to have to go to an even larger diameter reactor though. I based my design off of a lot of people seeming to have good luck with the 2 inch size and even shorter than what I have made. Hard part is sourcing caps in 3 inch size, seems to be the oddball in my area.
 
#20 ·
If you don't have a valve, you can improvise with some vice grips. Open them up so that fully locked, they only partially compress the tubing. More compression = closing a valve. It's not ideal, but it will give you an idea if adding a valve will help. If it works, then you can go forward with adding a valve.

Sent from my SM-G920V using Tapatalk
 
#21 ·
That's what I did except I used a cloths pin and some zip ties just so it was light weight and there was no risk of accidentally pinching through the hose. Plus each click of the zip tie is a tiny amount. I'll be checking on everything throughout tomorrow to see how it performs. Hopefully it'll be better. I can deal with a few tiny bubbles here and there but as long as I can get the pH to drop a full point or so with what I've got I'll be happy. Then I can upgrade later on when time and money permit.
 
#22 ·
Well as a bit of an update and a let down to me, with the line restricted and the co2 set at 2bps at 10 psi the co2 builds up way worse than it ever has. It's acting as if I'm injecting way too much co2 or that flow is too strong.

If I cut back on flow anymore I fear my filter won't be able to function correctly. So looks like I'll be having to build a 3rd reactor.

Anyone have any pointers besides going to 3 or even 4 inch pipe? The filter I'm using is a hydor professional 350. I have 2 of those, 2 sunsun hw-302's and a Rena xp-3 at my disposal so could it be a matter of too much pressure from the filter on top of water flow through the reactor?
 
#24 ·
From experience with Cerges reactors, I know flow rate is critical to avoid gurgling and CO2 build up inside the reactor.

You have several extra canister filters. I would use one solely dedicated to the RG reactor. Remove all filter media and let water enter at max flow rate into the reactor. Then apply back pressure to achieve the end result.

Sent from my Nexus 7 using Tapatalk
 
#27 ·
You need to find a balance. Too much flow = bubbles making it out of the reactor. Too little flow = a bubble forming at the top of the reactor. You need to find the sweet spot in between.

If you get it close, err on the side of too much flow, and then add a couple of hair scrunchies, bio balls, really anything to trap the bubbles before they make it out.

In my cerges reactor, I cut a ring of coarse foam that fits between the down pipe and the housing that traps any stray bubbles. It doesn't really impede water flow at all, but it stops any micro bubbles from getting out.

Sent from my SM-G920V using Tapatalk
 
#28 ·
That's the thing though, I can't find a balance with this reactor. It's like it's still too small. I've tried literally everything I can think of and it either does one thing or the other or sometimes both at once.

At this point I'm just chalking it up to still being too small. I can't even successfully get past 2bps without causing an issue.

This is honestly getting really irritating and if I had known it was going to be this hard to have an inline reactor I would've just gone with an inline diffuser.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top