aquarium live plants?

Question

in my 55 gallon fish tank I'm going to have about 5 or 6 piranhas. and some live plants for cover. do i have to have a co2 system? how much do co2 systems cost?

Answer 1

You don't have to have CO2. It depends on the plants you want. There are many plants that do not require high lighting or CO2 to grow, including:
Vallisneria
Java moss
Java fern
Giant hygrophilia
Anubias

If you do want to go CO2, you can do either DIY (cheap, but more work) or pressurized (expensive, but less work). This will enable you to have a wider variety of plants.

For DIY 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 :)



I must, in passing, mention my concern at your planning on keeping 5 or 6 piranhas in a 55 gallon tank. Piranhas are 12 inch fish. You can pull it off in a 55 gallon tank, but do consider cutting your numbers down and do not neglect your maintenance and cleaning schedule.

Answer 2

your piranhas will eat your vegetation, which could be good in nutrients, but you need to do some research on what is ok for them IF them do eat it.
Yes, you will need a filtration system, and ozygen for them. They can be messy buggers. Check your local pet store and tell them what you have, and ask what you need. If unsure, buy a book on the species of fish you have and read up. Internet searches can help. Try this link:
http://www.firsttankguide.net/piranha.php

Answer 3

piranha are really boring. The do nothing at all. Get some angels instead.
Piranha will eat all your plants.