CaRx ran out of CO2 while on vacation

[d2mini]

I have something similar -- believe it to be custom-built by "Alan Le"? However, unless it's broken but I don't recall observing the right gauge going from ~1000 psi to zero.

I've built my own and I've bought from Alan.
My experience has been that the bottle pressure will stay steady for most of the fill, until it starts to get near empty and it will slowly start to drop.
If it's not dropping as it starts getting low, might be a bad gauge? I dunno. Might be worth sending Alan a message. Can't recall if he's active here but he still seems to be on reefcentral.

Alan Le’s custom co2 regulators (DIY)

Hello Everyone! I wanted to share with you some of the custom co2 regulators I built recently. These are laboratory parts that I hunt from online and local surplus stores. They are very precise and work way better than commercial regulators.

forums.reefcentral.com

 

[Reefering1]

Interesting topic! As previously stated, weight is the only accurate way to guage remaining co2. Like all other refrigerants, to include co2(R-744), pressure can be deceiving. In simplest form..- imagine a car that the a/c isnt blowing cold. Customers says the "freon is full" because they bought a can with a guage and it showed 120 psi, evacuate it on a machine and it only pulls .1 lb out. A vessel under vacuum filled with any amount of refrigerant will balance out mostly liquid and some gas. The pressure will always be the same in accordance with the pt chart of the given refrigerant. Pressure means nothing. By the time the pressure starts to drop, it is virtually empty and falls fast as the remaining gas is vented. Or maybe the temperature of tank dropped and it's not low. That said, op's idea of having(remotely controllable) 2 part on standby is a good idea; assuming he practices and knows how much to add and when. Everything else can notify but doesn't really give a solution to correct the issue. Except maybe a ph probe to notify and second tank with a remotely controllable solenoid to switch tanks, but who wants multiple open tanks of co2 in their house, all the time, leaving your health/ safety depending on leak free lines and valves

 

[ca1ore]

My CO2 cylinders would last about 9 months …. and reliably so. If I was going away on the wrong side of 6 months I’d swap in the spare. Then go back to the original once back home.

 

[bakbay]

My CO2 cylinders would last about 9 months …. and reliably so. If I was going away on the wrong side of 6 months I’d swap in the spare. Then go back to the original once back home.

Well — I will set a reminder 9-12 months from now to swap out but was hoping for a semi-automated way. My Alk can drop 2-3 DKH/day so would suck if I’m out of town for a week/two.

By the time the pressure starts to drop, it is virtually empty and falls fast as the remaining gas is vented. Or maybe the temperature of tank dropped and it's not low.

That’s what I observed - unless my gauge is broken, I’ve never seen it moved tbh.

That said, op's idea of having(remotely controllable) 2 part on standby is a good idea; assuming he practices and knows how much to add and when. Everything else can notify but doesn't really give a solution to correct the issue.

I have an Apex + DOS (not currently installed) and can manually dose Alk remotely.

Except maybe a ph probe to notify and second tank with a remotely controllable solenoid to switch tanks, but who wants multiple open tanks of co2 in their house, all the time, leaving your health/ safety depending on leak free lines and valves

Interesting idea.

 

[ReefEco]

I do dose 2-part as well, so when I'm away, I make sure they are full, and can remotely increase their dosage if the reactor runs out. Also, I have a spare full 5lb tank (main tank is 20lb for the 600g system), so if things get really bad I can have a reef buddy swing by and just swap in the smaller tank. Some type of back up is key though, even if you are within your tank's 'normally still full' time period - crap happens! My backup tank that was sitting on the shelf next to the main tank and reactor randomly opened and bled all the C02 into the room one time while I was home - the seal on the tank broke I guess, so strange things can happen with pressure...

 

[Dburr1014]

My CO2 cylinders would last about 9 months …. and reliably so. If I was going away on the wrong side of 6 months I’d swap in the spare. Then go back to the original once back home.

Same for me as this statement.
About 9 months, I don't have a backup so I make room in a day to disconnect and swap it out.

 

[Karliefish]

One thing we can all agree on when it comes to this hobby...something will definitely go wrong at point

We all work hard to put in place redundancies to reduce failures. These include having two heaters (if not more) in a our systems. Having at least two return pumps and running them on separate circuits. Running half our lights on one circuit and the other half on a separate one. I think we all get the point here. I see this discussion as no different, i.e., we will run out of Co2 or worse yet, for some reason (only know to the fishkeeping gods) our CaRx will stop working. Therefore, the way I approach this problem is to create a backup (redundancy) solution, ensuring that my tank keeps getting adequate ALK and CA. Of course, creating a backup solution comes at a cost some us will be willing to pay and respectfully others won't be able to afford. Here is mine.

I have a APEX DOS system on standby that has a bucket of BRS ALK solution on the A side of the dosing system and a bucket of CA Solution on the B side. I use my Apex Trident system to conduct ALK and CA test twice a day. I've setup a program that basically tells my dosing system to dose ALK & CA if my ALK drops more than one point, e.g. ALk goes from 8,0 to 7.0. Once the ALK is back-up to 8.0 the dosing system turns off. Now I know that this backup system introducing its own inherent risk, but it does provide me with great peace of mine that my tank is getting vital trace elements while I'm away from home. BTW.....this redundancy system as already saved my butt once when my CaXr stop functioning properly.

 

[edd59]

a 2 stage regulator has nothing to do with 2 gauges, more so to avoid low pressure dumps. i have had a few regulators all single stage with 2 gauges. tank pressure and regulated pressure. now im using a single stage green leaf aquariums regulator. when tank pressure reaches 500 psi there is a shaded red part of gauge and states reorder co2. i always let it go to the red and lasts at least 3 weeks or more. right now its been sitting on the edge of red for over a week at 7 bpm. i run it close to empty somrtimes empty and never had a dump.

 

[Thales]

I think I remember Richard showing a scale on his systems in one of the episodes

Put it on a PM and replace it early is how I would do it.

Yep. After thinking about it for a few years and how to integrate it, I just bought a 35 dollar scale that plugs in and the CO2 tank sits on it. Every tank has the tare weight on it, just keep an eye on it. Pretty easy because the display is always on so I don't have to do anything special to check it but look on the camera or in person. So far I have learned that 20# tanks that you swap out are filled to only about 16#. Having the weight going down over time also means you get a real feel for how long your tank lasts. I am sure there is a way to have apex check it, but I haven't tried to figure that out.

There are some solutions for automatically switching to a new tank, Bill Wann did one, but they are complicated and cost monty. I find it much easier to always change to a new tank a week before I know I am going to be out of town. I also run kalk in case something borks with the carx