gauge

I have a question, I bough a regulator which show 3500 PSI and I want to buy a cylinder in the picture. I want to know which do you advise to get, the small cylinder (5L) or the Big Cylinder (7L). It will supply 3 planted tanks. I am just afraid if the big cylinder 7.2 Liters will damage the...

There is a huge price difference. I have read reviews on both and not many complaints on either. I like that on the dual you can have the bubble counter attached right to it. I'm not opposed to spending $100 or so on a dual but is it really needed? & What size tank would you recommend for a...

I just got a Aquatek Co2 regulator with solenoid. How do I read the gauge and what to look for? Another thing is that since my bubble counter is horizontal I can't count the bubbles unless I lay my tank down making the bubble counter vertical. Is it ok to lay the Co2 tank down instead of...