Why would you want to put CO2 into your fish tank?

Question

Why does one put CO2 into a tank in the first place? I have a 15 gallon tank and I've recently gotten some plants from a friend and he showed me everything that he's done to his tank and that includes putting CO2 into the water. What would be the benefits of CO2 and if I decide to do it how much would it cost for me to do it?

Answer 1

You put Co2 in the tank for your plants. Plants use Co2 for photosynthesis so they grow better.

Benefits: plants will flourish. More oxygen in water (plants are using the Co2 and expelling more oxygen as waste product). Some plants also take out the nitrate out of water.

Cost: depending on what you use. it could be really cheap to really expensive. Your tank is pretty small, so i suggest the DIY co2 yeast reactor. here is an article about what to do:

http://fishlesscycling.com/forum/index.p...

also, if my answer didnt satisdy you, here is another better informed article of what co2 is, how it works, dangers, and methods:

http://fishlesscycling.com/forum/index.p...

Answer 2

Photosynthesis....CO2 in O2 out....come on I'm 36 and have a little bit of remembrance of that from high school lol.....What kind of plants did you put in?  The more difficult varieties of plants, they do better with CO2 addtion in the tank.  I haven't done it, I only buy easy to grow plants, so can't say if it's better or not.

Here's a link for a DIY CO2, if it doesn't go directly to the page, click on plants at the top and the DIY is towards the bottom:

http://madhunag.tripod.com/

Cost is probably only a few dollars for the items you need.

Answer 3

CO2 will not do fish any good.  It could kill them in large quantities.  Adding CO2 would deplete the O2/CO2 ratio.  On the other hand, CO2 is what trees and green plants use to make chlorophyll and give off oxygen.  So for an all plant tank, CO2 would be ok, but with fish, you need to let the fish CO2 work with the plants in the tank.  A right balance will make a good ecosystem.

Ron

Answer 4

I forgot what CO2 means..... sorry=(

Answer 5

does your friend not have fish, or very little fish? If it is a mostly plant tank then its all right. but with fish everything should balance out.

Answer 6

You add CO2 to a fish tank in order to help the plants grow.  In a heavily planted tank, or for certain types of plants, adding CO2 is necessary for optimum plant growth.  Fish add some CO2 with their breathing, but in tanks with few fish and lots of plants, it may not be enough.  Fish need oxygen in the water, sure, but if there are tons of plants and only a few fish, there may be far more oxygen than they need and not nearly enough CO2 for the plants.  That's when adding CO2 is important to keep the plants healthy.  Having a tank full of dying plants is far worse for the fish than adding a little CO2.  There are lots of easy ways to make DIY CO2 infusers that take little more than an old soda bottle and a little yeast and baking soda and an air hose and air stone.  These cost only a few pennies to make and run.  You usually only need to add CO2 once a week or so to keep your plants healthy and thriving.

http://www.aquahobby.com/articles/e_co2....

Answer 7

Save your CO2 for your paitball gun and shoot your friend with a paintball.

Answer 8

some plants will get along without additional CO2 but all plants will grow better with additional. of, course, as so many have pointed out, too much CO2 is not good for the fish either. i have a 125 gallon low tech planted tank which i have purposely overpopulated in hopes of increasing the nutrients and CO2 needed by the plants. well, a couple of weeks ago, having nothing better to do, i decided to play with one of those DIY CO2 systems someone else mentioned. right away, there was a big difference. while my plants had been growing well for the past year with no additional CO2, when i started the CO2 dosing my plants just went wild and filled up the tank, so much that i have to trim the plants twice a week now if i want the light to penetrate the top layer.  plants that were so-so before grew faster and appeared more robust. leaves improved in color and size. even the anubias started growing new leaves almost daily.  now i'm thinking about going "high-tech".  

of course too much CO2 will lower the PH and poison the fish eventually. in everything, you have to find a balance, as some one else pointed out. i'm just wondering why there are so many thumbs down thrown at everybody when most of the answers did have some truth to them.

BTW, in answer to the last part of your question. how much $$$? depends on how much you're willing to pay, you could go DIY, cheaper but more work. you could buy the throw away types, or you could go all the way and buy the cylinder and controller system which will monitor ph and CO2 levels and adjust dosage accordingly. way too expensive for me.