how important would a co2 system be for my fish tank?

Question

i have a 75 gallon fish tank with a good amount of plants. They are kinda turning brown and leaves are dieing off. I just replaced my light strip i got wit the set up with 2 dual coralife t-5 freshwater plant lights. But i was thinking about doing a co2 system any thoughts on that. and how hard is it to maintain the system?

Answer 1

I think you'll definitely need a CO2 system at this point, and you'll probably need to go pressurized.
When you get past the basic java-fern-and-one-fluorescent-tube planting, you have to fine-tune the balance or you get dead plants and/or algae problems, because if you have one "strong" element (in this case, your lighting) and one "weak" element (in this case, your lack of CO2), you'll get straggly growth.

There are two ways to go with CO2. I mentioned pressurized, but you can try with DIY, first, to see if that works for you. DIY is less work to start up and more work in the long run, but much cheaper. You'll need:
One 2 litre coke bottle, rinsed
Some airline tubing (a few feet of it)
Sugar, yeast, and water
Something to diffuse the CO2 bubbles into the tank (lots of choices on e-bay - just do a search for CO2 diffuser) - OR, if you have a canister filter, you can just put the end of the airline into the intake of the filter.
So, take the cap of the coke bottle and drill a hole in it that is slightly smaller than the width of the airline. Take the airline and cut it at an angle so it has a "point". Take the point and stick it through the hole, then grasp it with pliars and pull it through - that way, it's perfectly sealed.
Put 2 cups of sugar into the bottle, and fill it with warm water up to about 5" from the top, and allow the sugar to disolve, then add one tsp of baker's yeast, and close the bottle.
Attach the other end of the airline to the diffuser, and put the diffuser in the tank.
You can do 2 or 3 bottles at a time, if you want. You need to replace the sugar and yeast once every month.

That's about all there is to it for DIY.

Pressurized CO2 is much more effective but, as I say, much more expensive. If you can find a used set-up, buy it, because it can be hard to gather all the pieces together depending on where you live. In short, you need:
A CO2 canister - a 5 lbs canister should last you for 6-12 months. (100$)
A dual regulator guage (40$)
A solenoid - this gives you the ability to the CO2 canister on a timer so you don't waste the CO2 at night when it isn't needed - you can get a guage / solenoid combo for 80$.
A needle valve to further control the output of CO2 - 30$
A bubble counter, so you can count how many bubbles per second you're getting (1.5-2 is usually the normal amount, but it depends on tank size, plants, KH and pH) - Milwaukee (THE CO2 brand) will probably send you one for free if you ask them, or you can find one on e-bay for 10$. Try to get one that prevents water from flowing into the canister.
Some CO2 airline leading into the tank
A diffuser - the "best" (IMO) is a small water pump pushing water into a spiral cylinder diffuser.

Anyway, those are the major outlines. You can likely find a used set up for 150-200$ but beware when buying used - my first "10lbs" setup ended up being a THREE pound cylinder with a busted guage, a cracked bubble counter, and a WAY too powerful water pump. Feel free to give me a shout if you want more info :)