The Planted Tank Forum banner

automatic change co2

3K views 15 replies 8 participants last post by  Tomislav Mirt 
#1 ·
Hello,
i open new thread and did not know if put in DiY or somewhere else.
i am doing big 400 gallons tank ( have thread 145 long tank) and ( because i am lot of time on trip from 5-20 days) want to put 2 or more C02 bottle with automatic change when one is empty so when i come back my tank have co2.
On net i find something name automatic changeover system for gas....if someone know if this can be use for co2 or can we DIY something like this or maybe some another opinion?
i find 2x 5 kg and 1x 10 kg bottle but probably put 2x 10 kg for tank.
Hope someone will know solution,thanks
 
#2 ·
Hmm,.why auto changeover? I "believe" you could just join 2 tank regulator outputs w solenoid/metering valve beyond that point.

You could prob. just join 2 tanks to one regulator but the plumbing of a 900 psi system takes special fittings, not just run of the mill piping.
 
#3 ·
Same question as Jeff, why auto change over?


as I said in your tank journal tread, your 400g tank holds most standards of its own, you need a different co2 injection method and I believe a 10kg co2 tank will last more than half year for co2 injection.

I will show the detail shortly.

And below is the dual co2 input system

Manifold protocol station with two pigtails(two inputs)
http://wikioldtown.com/catalog/E64_TAG_068.pdf
 

Attachments

#4 ·
i think that this is the same thing like i need….that is what i want...i need it ( if i am on trip when my cylinder is empty ) then put on another cylinder what is full.

Now one question if that make sense….is it good to bring 2 pipe for co2 one on left enter in tank and another in right so spread of c02 will be better or it is the same?

If is that ok.will i lose c02 until he come from cylinder to 5m long another side...
 
#5 ·
What is cheap and easy can work for some but that depends on each of us, so some personal thoughts on what might work best for you. Do you know how CO2 works and used it before? It has some things that often surprise new users, so add some details.
The way the gauges work on CO2 is different than like our cars. They show the pressure and that stays the same as we use the gas inside the tank and the liquid portion then becomes gas. The pressure reading we see does not change as we use gas until all the liquid part is gone and then the reading begins to drop. That means that we cannot use the gauge to say we have used half the tank in six months and we have six months left. So you will not be able to tell when maybe 90% of the gas is gone but if we are there and the gas is being used slowly enough that we may get a week or two from when the gauge begins to go down until it is empty, would that be enough time to let you turn on a valve manually to switch to the second tank. This is what many of us do as we see the tank beginning to get low, we have a week or more to get a new tank full connected as that is less equipment and cheaper. But if you have somebody watching the tank while you are gone, it might be simple to tell them to turn the knobs to open the second tank. I like to have somebody look in as things do happen that can make a serious problem if nobody looks but I do not expect them to do thing where they might become confused.
I try to keep all things simple when I can. Auto tank switches may be difficult!
For one CO2 input, I think it will be okay for even that large tank but that means water circulation needs to be good, both to move warm water and CO2 around to all spots but also it is needed to move loose debris around to the filter intakes. If CO2 is well diffused into the water, I find it does not come out when water moves from a tank end to the other. Testing in a 75 Gallon tank,I could not see a difference by where I placed the input, but that was only a four foot long tank, so bigger might be slightly different but not enough to make me worry.
 
#9 ·
On my last tank i have jbl proflora computer and ( not sure ) think that there was show when cylinder was low...

Bump:
I'd just set up two tanks and two CO2 systems and operate each at 1/2 the flow required. Simple and no autochange required. Plus you'd have redundancy, if one failed you'd still be injecting CO2

Regarding how much is left the tank, the easiest is to purchase an inexpensive fish scale such as a Rapala 50 lb scale and measure what the tank weighs. A bathroom scale would work also. You'll need to know what the empty weight is along with the weight of the regulator. I just measure mine with everything connected and it works great.
This is good solution with scale,but here is also problem later when i will know that when is weight on low ( maybe for 1 week or two ) and then i going on trip for 1 month and what then...empty bfore trip and change it ( but inside was maybe for one month left) ….make sense this?

Can You show us how do You do that with 2 co2?
 
#6 ·
I'd just set up two tanks and two CO2 systems and operate each at 1/2 the flow required. Simple and no autochange required. Plus you'd have redundancy, if one failed you'd still be injecting CO2

Regarding how much is left the tank, the easiest is to purchase an inexpensive fish scale such as a Rapala 50 lb scale and measure what the tank weighs. A bathroom scale would work also. You'll need to know what the empty weight is along with the weight of the regulator. I just measure mine with everything connected and it works great.
 
#7 ·
A very good thought here! Congrats on boiling it down to simple! Obvious and simple idea but Not one I've ever needed and did not come to mind. With use, the OP may find there is not really as big a problem as assumed there will be.
Since we do buy CO2 by the weight, finding how much weight is left is a pretty accurate way to find out what amount of gas we can expect to have.
Another thought if one is really wanting/needing two tanks and valve is that there is no need for the second set of valves to close off flow as shown in the picture above. The valves on the tank will be all that is needed so a simple tee fitting will do instead of the valves. That is also based on needing an untrained person to do the switch. No tee needed if we simply want to replace the tank with a full one.
 
#8 ·
Place the tank on a scale when full. Write the weight down can use a piece of chalk and write it on the tank. Then monitor the weight over the coarse of time and when the tank is empty write down the weight. You then will have a way of gauging when a tank will be empty.
 
#10 ·
If you insist that one CO2 tank be depleted before the other, so you can refill one at a time, then do the following:


Each CO2 bottle gets its own regulator. Primary bottle regulator should be set to 100 PSI
Backup bottle gets set to 65 PSI
Give each line from the two bottles a check valve and then tee the two bottle outlet lines together, to make a combined outlet. Feed that to the inlet of a third regulator. Set this regulator to something like 35 PSI or whatever you need. Connect solenoids, bubble counters, whatever you want, to this supply.

The first bottle will deplete completely, first, and then once it is drops below 65 psi, the backup bottle starts to dispense. At this time, you can completely disconnect the primary bottle and get it refilled. Once you do that though, you should make your backup tank your new primary tank, since you have already started using it, and you want to keep the newly refilled bottle as backup. To do this, you swap the regulator setpoints (100 and 65 becomes 65 and 100), the third regulator doesn't need to be adjusted.

Make sure you adjust setpoints while you are flowing gas, or you will make a mistake.
 
#13 ·
Part of the thought might be to look at how much cost and time or trouble to change a tank for a full one. Her in my area, the gas itself is very small and the charge is more for the labor of refilling the tank, not the gas itself. That makes a 5, 10 or 20 pound tank only about a dollar higher for each larger tank. Gas prices are different and how much trouble it is to take the tank and get another full is different, but in my case, it seems wasted gas but changing the tank before it gets totally empty is cheaper and easier than working to arrange to let it go totally dry to get the value of the gas but have to be ready to go get new, even if it is not convenient. I drive about ten miles to a welding gas shop to get the best price, so doing it on a special trip costs more than just doing it when there is still some gas left in the tank but I am going that way for something else. Bigger tanks are far cheaper to refill than smaller but that also has to fit how we each live. I throw a 20 pound tank in the car and find it works for me but if I had to ride a subway and walk three blocks to get the tank home, small would be better!!!
 
#16 ·
yes that is what i need only much simpler and cheaper….when buy will put picture.

Now want to put co2 on left and right side of tank for better distribution co2....Is this good or is same if gone only for one side?

I read that someone told about wave pump for better distribute but i did not mean put taht pump in tank.What think is needed?Because will be lot of plant and dont know will have effect...
 
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