Need help figuring out how to split co2 output in tank

[jonatheber]

I have a 46 gallon bowfront tank with a fluval canister filter located about 85% of the way towards the right of the tank and with the outflow directed towards the left along the back of the tank. I currently have a CO2art regulator hooked up by CO2 hose to a single large diffuser pushing the co2 out directly under the outflow of the fluval, which covers the middle and left of the tank (all are doing quite nicely, no algae, etc). However, the right side of the tank to the right of the outflow, which is at the end of the water current, has far less growth. I bought another diffuser and am hoping to somehow split the CO2 output 75/25 between the main diffuser and the extra one I just added.

My problem is that I can't figure out the best way to do the "splitting." I found an ADA Nature Y splitter, but that would take the CO2 and dump it 50/50, which would have way too much on the right side of the tank and not enough moving to the left side. I tried to find a valve of some sort I could put in the CO2 hose but have been unsuccessful (other than ADA Nature, which sells them for $35 each and that seems sort of inefficient). The LFS suggested I consider something like this, but that would require me to get two bubble counters and somehow hook them up to the splitter.

Any suggestions would be VERY welcome. Does the LFS have the right idea? Should I try something else?

 

[Colin_T]

plastic T piece?

 

[StevenF]

The variations in diffusers one will cause one to require more pressure than the otherto operate properly. This variation means one will work while thether will not.

The best way to do this is to have one regulator on the bottle to drop the pressure down from about 800 PSI in the tank to say 30 PSI. Then split the line with a T or a Y fitting. Ten on each branch of the CO2 supply you have another regulator or a needle valve so you adjust each line separately to to get uniform flow from each diffuser.

I worked in the semiconductor industry and with virtually all the gas we used. A regulator on the bottle the lines would split to multiple pieces of manufacturing equipment and the at each tool the there is another regulator and from there we had a flow controller (an automated version of needle valve).

However with two lines probably will need to constantly (maybe once a day) adjust the needle valves It isproably better to have one regulator and needle valve for each branch. Don't bother looking for flow controller, you can't afford them.

You probably have CO2 drop checker in your tank to insure your CO2 levels are safe (too much CO2 can kill fish). If not get one. Once you have our one diffuser running place the drop checker somber in the tank. After a couple of hours move the drop checker Every few hours move it. you will probably find the CO2 levels are very uniform all over your tank. If not try increasing the flow from your water filter. With enough water flow CO2 would be spread unformaly throughout the tank.

You might want to look at passive CO2 systems. If is much more efficient ( your tank of CO2 will last longer) with CO2 and it is impossible to get CO2 levels too high to kill your fish. And amazingly you don't need a drop checker. I use passive CO2 in my small strimp tank (5 gallons) and it works very well and I don't use a drop checker.

 

[TwoTankAmin]

It has been a while since I ran pressurized CO2 system. Back then there were not many all in one systems. So I had to research yours. What controls the flow of CO2 into the tank is the needle valve. Your system has one as part of it: "This CO2 regulator comes with a bubble counter and an extremely precise needle valve...." Next, the way you see any adjustments you make to the flow of CO2 is using a bubble counter. It lets you set the bpm (bubbles per minute) rate. Your system has one.

What it done in splitting the CO2 in two (or even more) tanks is to provide each tank with its ow needle valve and bubble counter. I am not sure htis is possible with your system as everything is included.

The initial output from a CO2 cylinder is way greater than needed and the knob on the tank dooes not permit anywhere near the control needed over the system. So the first syage is a regulator which lets one do the first needed reduction in output. But even this is not a fine enough control. This is obtained with the needle valve. And the bubble counter lets you see the effect of any change you make in the flow rate.

So you need to split the output of your system beforethe needle valve. You need a T or Y splitter. This must accept a needle valve on each of the two outputs. You will then need CO2 resistant tubing which then leads to a buuble counter and then from there to however you will disperse the CO2t into the tank.

I do not know if you can take apart your system to move just the needle valve and bubble counter which you now have. You would have to deal with splitting the output from the cylinder at the point where you detached the current needle valve. From there you need to feed the CO2 into the T or Y.

The most important consideration when you desigh what will be placed where, is that you can see the bubble counter from wherever you are adjusting the needle valve's output. Basically think of it as a more complex form of multiple airlines from an air pump stronger than needed and with just a single output on the pump.

One last caveat. Get a small roll o 1/2 inch wide teflon tape. Most any threaded connections should use this. I blew out my first 5 ponds of Co2 in about a week. After I tape myconnectes my 5 pount tank lasted for a bunch of months. And that brings me to te final advice I can offer, When a tank gets refilled the comlpressed gas is very cold. The bottle can be very cold if you are having your exact cylinder filled on the spot or exchanging the empty for a filled one that ws recently filled. Starting with my second refill I always brought a pair of gloves with me. this included the middle of summer when it was in the mid 90sF.

 

[jaylach]

My question is why, exactly, do you need CO2? It is really only needed for certain plants and isn't normally good for fish.

 

[TwoTankAmin]

CO2 is most certainly not bad for fish in the concentrations one normally gets in a planted tank. Of all the tanks I have had over the years I would say that my one high tech planted tank with pressurized CO2 was probably the healthiest tank I ever had. I never had any fish get sick in it in the close to a decade for which it was set up. I never medicated the tank for anything. I had Farlowellas spawn in it.

The whole point of adding the CO2 is that the plants in the tank use it faster than it can be replaced from surface agitation. But most plant will benefit from a bit of added CO2. However, this is not the same as suffering from a deficiency of it and needing more added to address this.