View Full Version : How much CO2 should i use?

7th Jul 2008, 04:25 AM
i just got a 5lb CO2 tank and a CO2 Solenoid Regulator and bubble counter. :)( i still need some advise on a good diffuser? :huh:) i just want to know how much CO2 should i put in my CRS tank to grow REALLY healthy fissidens?? :bs_help:

7th Jul 2008, 04:24 PM
First how many liters is it and the plants that you have and as much info as possible.

9th Jul 2008, 03:06 PM
Hi, it's good to start off slow, like 1 - 2 bubbles per second initially and you can up it as the plant growth gets denser. However - if you are growing in a new tank without any livestock in yet it's good to hit it hard like 5 bubbles a second to really get the plants growing fast and keep algae at bay. It also depends on your type of livestock. Fish can only take around 40 ppm as a general rule (it varies with the breed) but shrimp can take much higher levels than fish. So a shrimp only tank can have higher co2.
The easiest way is to buy a CO2 drop checker from ebay or somewhere. It's a glass ball with a sort of horn openening. It comes with solution that you put in it and when your c02 is at good levels (around 30 ppm) it goes green. If it's high or low it goes yellow or blue. As far as a difffusor it depends on the size of your tank and you taste - I like the clean simple looking ones as opposed to the ones with the flowery sort of glass edging. Bigger is usually better unless you tank is tiny. There is also a company called "Cal Aqua" that makes inline diffusors if you don't want it in your tank. There are ones on ebay that are fine, you don't need to go all Amano on it, as they are dear. One thing - never hold the diffuser by the stem when you suction cup it to the glass. The glass is very fine and will break. I've broken a few...
Also - you don't mention a checkvalve. You need one in between the bubble counter and the regulator or you risk water being sucked back into the reg when the solenoid is turned off at night. Brass ones are better than the glass ones, although the ADA Cabachon Ruby looks beatiful works well and is reasonably priced.

Of course all this assumes you have enough light and ferts to take advantage of the added CO2. Any other questions please ask away...it's confusing at first but pressurized CO2 rules....

9th Jul 2008, 08:18 PM
I have a 20g and running 2 bubbles a second with excellent growth. You could go more depending on the ph of your water.

10th Jul 2008, 03:20 AM
will the co2 raise or lower my ph?

10th Jul 2008, 06:43 AM
CO2 will lower your ph. How much will depend on your Kh and how heavily planted the tank is. Plants take in the co2 and release oxygen into the water during the lights on period but not during lights out, so that's why you need a solenoid to turn the co2 off during the dark period, otherwise your ph would drop lower and your tank will experience large ph swings which is bad for livestock. Also don't forget that surface agitation releases co2 from the water, so if you're running a co2 tank, an air bubbler shouldn't be used as it pretty much makes the water release all the co2 you are pumping in.

11th Jul 2008, 04:20 AM
20 - 30 ppm
needs to be measured accurately with known kH water in a drop checker and a pH CO2 chart... this removes all other sources of pH change from the equation so any colour change is due to only carbonic acid

carbon is probably not essential for most mosses as they grow slowly anyway