I think i read on here to put my needle valve after the regulator but im not sure why. What is the purpose of adding it after the regulator? Is it only to fine tune the bubble count? If so i guess i dont need it because i dont have a bubble counter anymore. If there is another reason please let me know. thanks
The way a regulator works is that it tries to keep the output port at the desired output pressure. If there is no restriction on the output then it will keep blowing gas until it either finds an enclosed volume to bring to the output pressure or until it empties the CO2 tank.
You need a restriction of some sort, usually one with fine tuning, hence a needle valve.
A needle valve will allow fine-tune control of the flow of CO2. A bubble counter is only an extra piece of equipment that allows you to easily visualize the CO2 flow.
You will still need a needle valve (which goes after the regulator, as you mentioned) if you are going to be using pressurized CO2.
The needle valve will also prevent an end-of-tank dump of co2 into the tank, from my understanding. I'm still on my first tank so I haven't had a chance to test this yet.
The idea is that you set your regulator to about 10psi or so, and then use the needle valve to fine tune it to what you need. I don't use a bubble counter either, kind of useless to me since all that matters is how much is saturated in the water.
EOTD is a complete misnomer. The pressure rise at the output chamber of a single stage regulator is progressive, well understood and begins when the tank no longer has liquid CO2 and starts to lose pressure. There is no "dump" unless something completely fails downstream of the regulator.
If you normally only run 10psi the pressure rise may be 20psi as the tank finally empties resulting in 30psi total. Obviously your CO2 delivery rate will rise and if you have your needle valve set for 30ppm the 30psi will likely give you more like 90ppm assuming your reactor can actually process that amount.
So to minimize the issues it is actually better to run at a higher pressure rather than a lower one to minimize the percentage increase. This may be difficult with a sloppy needle valve.
At the point your tank no longer has liquid CO2 there is only 10% of the capacity left. At 400psi there is only 5% left and the output chamber pressure of a single stage regulator will have risen by 5psi or more. Since the fill cost of a tank is <$30 anywhere, saving $1.50-$3.00 to get the last mole of CO2 out of a fill seems a bit foolish if you have any fish at all.
I understand what is being said but. I set my co2 at 20 psi with the regulator then i can adjust the needle valve all the way open to almost all the way closed without any noticeable flow rate change the only noticeable change is when closed the bubbles stop completely. the gauge on the regulator never changes when adjusting the needle valve. So how do you fine tune with a needle valve if there is no way to measure what the needle valve is doing? am i missing some piece of equipment? I hope i wrote this correctly to explain what info I'm looking for. thanks
You either have a crappy NV or the orifice inside that controls the flow of gas is damaged from over tightening (dont ask me how I know about this). There are plenty of good NV's to be had for under $50. I know that's not chump change but after you have one there's no going back. The ability to control bubble count down to one bubble per 1-2 minutes is pretty impressive. Not that we would need that slow of a rate but you understand im talking about total control here.
Swagelok, Ideal, and a few others are good name brands to consider.
The only way that you can prevent EOTD is with a Dual Stage regulator. Its not necessary to have one but IMO its cheap insurance for my tank. Plus they are pretty!
The gauge is never going to change when adjusting the needle valve. The needle valve is AFTER that gauge and has nothing to do with it. You need to get a bubble counter, or if you are using a glass in tank diffuser, you watch based on how much flow.
Get a bubble counter. You HAVE to be able to tune the rate you are injecting. You can't just let it all go.
The low pressure gauge tells you what PRESSURE you are feeding to the needle valve, and then you use the needle valve to adjust the FLOW of co2 into your tank. If you just inject at 20psi with no NV to adjust it down, you'll end up with far too much co2. LIkely you'll also just waste a ton of gas.
Ok. I do have a dual stage reg I'm about to hook up right now I'm using a single stage. I guess that is where I was going with the post I guess I need a bubble counter to be able to adjust the needle valve properly. Right now I'm running 20 psi and it's staying steady and the drop checker is nice and green. Thanks guys
Yep, a BC is a must. You dont need to buy one. If you have some extra tubing, a clear plastic bottle with a good seal on the cap and preferably a few inches of hard line you can make your own.
Thanks for clearing up the tank dump think, no need to laugh at me heh, I only know what I've read - and I'm sure I read that on an old post in this forum.
But I have read that, and it made sense because the needle valve is set to only allow a certain amount of pressure through. That's why I have it - I can fine tune it quite well with this unit.
A needle valve will not keep your bubble count at a constant in all circumstances. If your output pressure is increased, you will pump more CO2 into your aquarium, even if your needle valve hasn't changed.
My dual regulator keeps it at a constant 10 psi, why would it suddenly change?. My needle valve keeps my 'bubble count' steady, and has been keeping my co2 levels steady for months. I really don't get some of what is being said. I know I'm not the only one out there who doesn't use a bubble counter.
My dual regulator keeps it at a constant 10 psi, why would it suddenly change?. My needle valve keeps my 'bubble count' steady, and has been keeping my co2 levels steady for months. I really don't get some of what is being said. I know I'm not the only one out there who doesn't use a bubble counter.
i simply gradually turned it up using the needle valve a little bit at a time until the drop checker sat at a nice colour. to me patience is one of the most important tools in this hobby and it doesn't cost a dime. Clearly just suddenly jetting a bunch of co2 into the tank wouls be silly.
+1 to above that is exactly what I did.
The only reason for me buying a bubble counter now is to set my needle valve for this end of tank varying of the co2.
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