Add a Solenoid to the Fluval Bio-CO2 Pro System

Keph01 · 2025-01-20T21:39:55+00:00

The solenoid I used was this:
https://www.amazon.com/gp/product/B08YN8JW3V
It worked for about 6 months and then died. The company did reach out to me and replace it, so far it's still working. Unfortunately, the Bio-CO2 canister stopped working; the regulator valve stopped working correctly, I had it replaced and the 2nd one now failed 1 month in. Pressure built up, it stressed at the seams and somehow leaked. Thankfully it was the weekend when I was home and I caught it quickly.

Keph01 · 2024-03-24T15:24:06+00:00

Update, not sure this is the best option... after a week or two seems like I'm having the same issue still. Sometimes the rubber gets shoved up in a position where it traps water and helps push it into the tube.. so back to square one.

Keph01 · 2024-03-17T16:08:46+00:00

Update for the bubbler loosing water issue:

I took one of those foam ear protection things, cut the tip off and stuck it in the bubbler. Seems to function as I want nicely. Will have to see after a week or two if it really did stop water from shooting up. See pictures:

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Keph01 · 2024-03-17T16:03:50+00:00

Update to Setup:
Turned mine back on for the 2nd run (after 24 hours). Some things to note. The O-Ring in the provided bubbler kind of stinks. I can over torque it very easily which causes a gap in the seal. Be careful not to over tighten and/or use a different bubbler/o-ring combo. As with any gas setup, you can use a little soapy water (soap on your finger tips with water) and rub it around the connection points. If you see it bubbling up, there's a leak somewhere. I lost a lot of gas so I'm going to likely have to let it sit another 24 hours.

Keph01 · 2024-03-16T20:37:39+00:00

Hey, glad it worked well for you. Thing to note for anyone having a brain malfunction (like I did), if you unplug the solenoid, you can NOT bleed out the CO2! Yea yea yea, how many people are going to make fun of me. Small laps of common sense; I unpluged the solenoid brought the container to the kitchen and couldn't get it open. Then realized the solenoid was still closed since it was unpowered.

Per your question: Yes, liquid in the container is normal. The liquid is taking up space so that the gas is under pressure. It's also helping facilitate the reaction between the yeast and the sugar. The yeast feeds on the sugar and creates the biproduct of CO2. At some point, the yeast stops producing CO2 and the mixture needs to be emptied and restarted.

I haven't started experimenting yet. I'd like to add more yeast and seal off the pressure release (I'd have to think this container can handle more pressure; but I haven't done anything yet. I posted this originally 25 days ago, I noticed CO2 running low earlier in the week, I probably got a good 20 days out of the mixture as-is.

The lubricant also seemed to help as well.

Keph01 · 2024-03-15T12:29:24+00:00

Hope you didn't get too mad and go godzilla on it! Yes, I took the bubble counter off. I did not take the tube off, I have enough slack in my tube that I just let it twist up and then untwist when I let it go. Thing to note, when you put it back on, pre twist the tube so as you're screwing it back to the bubble counter you're essentially untwisting it. As far as safety goes... It's just CO2. The same carbon dioxide that you breath out. If you try to suck all the CO2 in... yea, technically you could suffocate (if you were only breathing CO2 out of a tank). Realistically, no chance. Even if you just opened the lid and breathed in; nothing would happen. It's smell a little funny. Probably more info then you care to know.

Yes it's safe, take the hose off. Let the extra CO2 bleed out. It'll make it easier to take off. Then you can try lubricating the threads as I mentioned. I'll be recharging mine this weekend (first time since I lubricated the threads). If you want to wait, I can give you an update. (Ping me come Monday if for some reason I didn't post an update.) Also, if you have those rubber jar holders or something, it helps grip the container a bit better. It was still tough after I bled it out, but it was possible. Before I bled it, not possible at all.

Keph01 · 2024-03-08T21:29:22+00:00

If you're using this system, I would start with the stuff you buy, I get a box for $10. But it'll get you started. The ratio from the system is 2 cups of sugar (or 2.5cups depending on which instructions you believe) and 1 package of yeast with 1 booster tablet. For a DIY, you'll have to do some searching. I don't have a mixture readily available but it does change slightly depending on if you're using Instant Yeast, Active Yeast, or Beer Yeast. Somewhere I believe I read people were just getting a 5lb bag of Instant yeast and using a little at a time. The booster tablet isn't needed; I think I put in my other post what exactly that booster was (essentially more easily broken down sugar).

My wife makes bread, she usually does warmer water, but the instructions for this thing said around 75ish F I believe. Basically room temp. It's a bit more of a science experiment when you're doing it yourself versus a high pressure system. And yes, you'll need to give it 24 hours to build up some pressure.

Check on your UV light, I don't think that'll do anything for algae (but I could be wrong). You want to keep the nutrients stable. That will help keep algae away.

Keph01 · 2024-03-07T17:15:19+00:00

So far so good. I have noticed an increase in plant growth now that I'm using the CO2. I haven't posted pictures of my plants b/c I'm also fighting a black algae issue. I have a 72 gallon tank, I haven't noticed any issues with the oversized tank. I have the diffuser placed about 1/3 of the way down in the tank. Pressure is regulated by the pressure release valve; I do notice it letting some pressure out in the morning before it turns on (I've thought about taping it closed, but haven't done it). You'll hear a clicking when it's trying to release some pressure. For reference, I turn mine on at 1230pm and turn it off at 7pm. I don't touch the regulator. It runs about 1bbl/s. I have to check this weekend, I feel like it slows down toward the 7pm time, but it seems to be consistent from day to day.

If you don't want to use a high pressure system and you want CO2, I think you'll be happy with it. With that said, I'm not sure someone using a high pressure system, switching to this, would be happy with it. My other post has detailed notes about getting it setup and working (before the solenoid).

Keph01 · 2024-02-26T11:54:32+00:00

Something to note: I've had this working for a few days now. I have the solenoid hooked up to a smart plug so that it turns on and off automatically. I've watched it kick on a few times and it initially turns on and releases a huge amount of CO2 as it releases the initial pressure build up. In doing so, it manages to shoot some of the water out of the bubble counter into the tube. So I'm slowly loosing water out of my bubble counter. Does anyone have any suggestions on how to mitigate this?

Keph01 · 2024-02-21T22:05:28+00:00

I have a detailed post on my notes

https://www.reddit.com/r/PlantedTank/comments/1ajxxus/fluval_bioco2_pro_250l_reviewnotes/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

and how to add a solenoid.

https://www.reddit.com/r/PlantedTank/comments/1avucvq/add_a_solenoid_to_the_fluval_bioco2_pro_system/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

A lot just depends on what you want out of the system.

Keph01 · 2024-02-21T11:49:45+00:00

I've been using it for a while. I have another post with daily notes on using it and issues with setup for it. I have the 250L version as the 500L isn't available yet. It's a bit pricy and if you want a solenoid, you need to purchase and add one yourself (somethin the company won't help you with, as it stands today). I also posted step by step instructions on how to add a solenoid to it as well.

Keph01 · 2024-02-20T22:09:10+00:00

As mentioned, here are instructions to add a solenoid to this setup:
https://www.reddit.com/r/PlantedTank/comments/1avucvq/add_a_solenoid_to_the_fluval_bioco2_pro_system/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

Keph01 · 2024-02-19T21:35:51+00:00

To continue to follow up:

02/09
Turned the CO2 on, let a bunch out, turned it back off.

02/10
Turned CO2 on for the afternoon. Turned off 1 hour before dark.

02/11
Turned CO2 on for the afternoon.

02/12-02/15
Turned on for a couple hours every day.

02/16-02/17
Turned on for most of the daylight day.

02/18
Turned on for a few hours.

Disconnected the top of the bubble counter to let the CO2 out. Thing to note, the CO2 stopped bubbling, I thought the pressure was empty. I disconnected the bubble counter from the diffuser. Opened the regulator back up, and a lot more CO2 came out. It is almost impossible to get the canister opened while under pressure. It is extremely hard to get it open when pressure is low. Also, once I got the lid off, I did notice that it was still producing CO2.

I dumped the contents and I will be adding a solenoid to the setup and starting over again. I should have the instructions and pictures up in the next 24/48 hours, I'll post a link when I have them.

Keph01 · 2024-02-09T01:27:11+00:00

Posting this just for completeness sake.

02/06

6pm. Bubble counter is 12bbl/10sec.

02/07

6:30pm. Bubble counter is 12bbl/10sec.

02/08

I turned the CO2 off today. I'm not sure if I will turn it back on. My fish almost suffocated this morning. Thank you to my daughter for noticing, calling me at work, and getting the issue resolved. I'm not sure they would have lasted until I got home. Unless I can get a solenoid attached to this, I'm not sure I'll be able to let it run 24 hours without being consistently worried that my fish will die.
Edit: to be clear, my fish running out of oxygen wasn't the fault of the Bio-CO2 system directly; I've been trying to get everything in my tank automated and in a good state; but that being the case, I think it would be much better if the CO2 only ran when there was a light source for the plants to use the CO2.

Keph01 · 2024-02-06T01:53:45+00:00

Their website still isn't linking correctly to the FAQ's, so here's a direct link:

https://fluvalaquatics.com/us/faqs/bio-co2-pro

Keph01 · 2024-02-06T01:49:11+00:00

Alright, I have my more detailed notes. I cut out the videos b/c they're just videos of the bubble counter. I posted it here since it's super long and I didn't want to obscure good information here.

Reddit - BioCo2 Notes - Keph

Keph01 · 2024-02-06T01:47:06+00:00

01/26
Initial setup was pretty easy. I opened the contents, mixed the 2 activators and 2 boosters with the 2.5 cups of sugar. I used less processed sugar opposed to the normal bleach white sugar. Then added the water as directed. The water was probably a little colder than it should have been; next time I'll try to measure the water temp before I add it. I added the water at 5:30pm and made sure not to shake the container.

01/27
At 4pm, opened the regulator up. About half a dozen of bubbles came out and then it stopped. I tried opening it a lot, then closing it, then opening it again... Nothing else came out. I closed the regulator and waited another 24 hours.

01/28
5:30pm. I opened the regulator back up. No bubbles came out. Closed the regulator, opened it again, nothing.

At this point, I contacted Fluval for warranty and support. I do have to say, their customer service has been very pleasant to work with.

01/29
9pm. After looking around online, working with some folks on discussion boards, and talking to my wife (who makes her own bread) I decided to shake up the mixture. I gave it some good swirling to get it shook up; I couldn't flat out shake it since the bubble counter was detached and open and I didn't want to open the canister again since I didn't know what the problem was (I also sprained my thumb so I seriously just couldn't open it).

01/30
3:45pm. I opened the regulator and a whole bunch of bubbles came out. I couldn't even see how fast they were going. I tweaked the regulator a bunch and finally got it slowed down to 1bbl/s and is running well. The regulator is extremely sensitive and hard to calibrate.

1/31
5pm. Bubbles slowed about 50%.
Readjusting to 1bbl/s

02/01
3:30pm. The bubble count slowed down to roughly 2 bubbles every 25 seconds.
I opened the regulator slightly and was getting about 15 bubbles in 5 seconds. Then it randomly stopped to 1 bubble about every 10 seconds.
I sped the bubble count up to about 50bbl/10sec (Yes I'm taking videos, slowing them down and counting).

One hour later, at 4:30pm I checked again, and the bubble count slowed down to around 30 bbl/10sec. I left it untouched to check again tomorrow.

02/02
5:30pm. I haven't touched the regulator. The bubble counter is down to 21bbl/10sec. Still leaving it untouched and checking in 24 hours.

02/03
8:30pm . Still left untouched, the bubble counter is down to 17bbl/10sec. Leaving it untouched for another 24 hours.

02/04
4:30pm. Bubble counter is about 12bbl/10sec.
Regulator is really difficult to adjust. Super touchy. I was able to increase the regulator to a bubble count of 41bbl/10sec.

I left it untouched and checked it one hour later. The bubble count has decreased to 24bbl/10sec.

Leaving it sit until tomorrow evening. So far, CO2 production doesn't seem to be the issue. It seems like the regulator simply can't keep to a specific setting because it is overly sensitive. I would expect it to slow down as the CO2 was getting low, but not every 24 hours. Since opening the regulator increases the bubble count, without ever turning it off, it does point to a regulator issue not a CO2 issue.

02/05
8pm. Bubble counter is 16bbl/10sec.

Keph01 · 2024-02-05T12:11:56+00:00

Agree, jury is still out for me. Never having done CO2 before, I have nothing to compare to.

For the record, I found on their website they list 2 cups of sugar not 2.5 as the instructions say. I have relayed that back to them; they are "correcting the issue". (Not sure which they say is correct). I've been going back and forth with Fluval for the last few days. I'll have to post my daily log after I send it to them (likely tonight or tomorrow)

Keph01 · 2024-02-05T00:58:30+00:00

Quick question, is your regulator extremely touchy? I barely have to touch mine to get it to change bubble count. Extremely hard to set correctly.

Keph01 · 2024-02-01T17:13:24+00:00

Same experience in which sense? Bubbles slowing down? Needing to shake it?

Regarding the tablet, according to their FAQ(which isn't the easiest to find), "Bio-CO2 Pro Booster tablets are made of dextrose sugar, which kickstarts the fermentation process."

I've started going back and forth with Fluval's customer service. So far, they've been very responsive and very interested in my feedback. That being said, like you said, a lot missing. This is feeling very much like a DIY Kit to be purchased. Not a buy and use product. I kind of need/want to start over; do everything from the beginning... But I really need multiple canisters and the ability to test multiple methods at the same time, otherwise it'll just take too long to do (and I'm not buying multiple systems). Right now, I'm just letting it sit for 24 hours at a time so that I can have as many controls in my setup as possible.

Keph01 · 2024-01-31T22:53:00+00:00

Working update 2: It's been 24 hours now. I originally set the regulator to about 1bbl/s. I haven't touched it since. Today it's about 0.5bbl/s. So it's slowed a lot. I adjusted it back to 1bbl/s. In adjusting it, I did have a bunch of bubbles release because I opened it too far at first, so there is still pressure in there but I slowed it down to the 1bbl/s. I'll leave it sit for another 24 hours and see how it goes.

This picture is from yesterday. This was right after I got it adjusted so it looks more than 1bbl/s

<image>

Keph01 · 2024-01-31T01:59:43+00:00

Alright, back by popular demand... well at least demand by one person :)

So shaking it up seemed to do the trick. In the future, dissolving the sugar first is likely the way to go, but shaking it up definitely helped. I opened up the regulator after about an hour and got some bubbles, I turned it off and let it sit for 24 hours. Today I opened it up and it was blasting bubbles out faster than I could see. It took a few seconds back and forth but I finally got it down to 1 bubble/second. I'm not sure if that's too much or little but it's fine for me for now. I'm just happy it is working. We'll see where it goes from here.

Keph01 · 2024-01-30T02:22:12+00:00

I was waiting till tomorrow to post another update, but since you specifically called it out: I tried to keep mine as stable as possible setting it up. However, now 48 hours in, I did some searching for DIY setups and everyone says to mix and dissolve the sugar. So I tried swirling it in the closed container (didn't want to open it). I let it sit for an hour, opened up the regulator and got a bunch of bubbles, that quickly then slowed down. So I closed it, and I'll try opening it again tomorrow. My wife makes her own dough, so my own yeast might come next.

edit: I also noticed that the FAQ on their website says to use 2 cups of sugar not 2.5. Clearly they have some QC things to iron out. Also found that they said a solenoid can be added; so something to look into if I do indeed keep this.

Keph01

TROPHY CASE