co2 for freshwater plants?

Question

I have a 75 gallon freshwater fish tank with allot of plants, which i am trying to replicate my dads tank. i want more plants but it seems that they are not doing to well. I use the normal kent growth stuff but i have been reading about co2 systems.

I am not sure what it does fully or what i would have to do to set it up or what i need to set it up. And help would be great and options that anyone knows about.

I have also heard that it is dangerous? not sure what that ment lol.

Answer 1

Plants need this in order of importance: Water - Light - co2 - Mineral Nutrients - Oxygen

Your plants are constrained by the weakest link in the chain. Fish will never add enough co2 via respiration. That's just foolish. Most fish respiration generated co2 is burnt off in the first hour of plant respiration and the plants are left to starve the rest of the day. If the plants aren't producing visible oxygen bubbles then they're lacking something. Just like you can see a fish breathe, you should be able to see your plants breathing if they're not just slowly dying. If you're adding fertilizer without high light & co2, you're probably just feeding algae since the plants will not respire enough to use any of it.

If a plant is starved of co2 long enough, it will strip its outer cell walls in a last ditch effort to alter the ph of the water, and absorb trace carbon elements. Its called Biogenic Decalcification. This will make it look like the plant is dying. Its kinda like stabbing a hole in your arm to drink your own blood because you're thirsty.

If you want a forrest of plants you need to let them breathe co2. Flourish Excel is a product that can help many plants, but its not as good as a co2 injection system. Excel can be a good stop gap measure for people getting started in aquascaping, but its not as good as the real thing. It will keep many plants from dying though.

There are 2 ways to add co2 to your aquarium. a DIY Yeast / sugar bottle, or a compressed tank, kinda like a helium tank thats used to fill up balloons. For a 75 gallon tank, it would be a lot cheaper in the long run to do the compressed tank route, as you'd have to use like 8 cups of sugar per week & 2 teaspoons of yeast for the yeast method to provide adequate co2 saturation in a 75 gallon tank.

The initial cost of a tank based co2 system is high, about $125, but the maintenance costs are about $5 every 6 months to recharge the cylinder. In addition, the compressed tank method allows for more stable co2 concentrations since the output of the unit is not dependant on the environmental conditions of yeast eating sugar.

co2 can be dangerous if it isn't monitored closely or administered at the correct rate. Co2 produces carbonic acid when it goes into the water, which lowers the ph. If the KH (carbonate hardness) isn't high enough in the water, it can cause an unhealthy shift in ph between night & daytime when the plants stop using the co2 and begin consuming oxygen. This can be fixed by regulating the flow of co2 at a constant rate that doesn't saturate the water above 30ppm of co2, increasing the kh of the water with baking soda, or getting an electronic ph monitering solenoid for the co2 dispenser, which will shut off the co2 gas when the ph goes below a certain level.

You may also want to check your water parameters versus the plants natural habitat. tropica.dk has some temperature, gh & ph scales for popular plants. If you're trying to grow a plant that likes soft, cool water in a tank that has hard warm water, that will also cause your plants to die, co2 or none.

Answer 2

Plants need nutrients to grow and carbon to prohibit photosynthesis. In my 55gallon I do not have Co2, but have had much success with my aquatic plants. I use the Seachem Flourish for nutrients, and Seachem Excel for an organic liquid carbon. These products are about $15 each and will last approximately 2-3 months w/ proper dosage. Before I spent all my funds on a Co2 system, cartridges and everything else I tried this and have had plants grow, and make babies and have the baby plants grow.
There are DIY Carbon Dioxide set ups made from a 2litre bottle and some baking soda. I've attached a link below that will go through everything for you, if you need Co2, what it will do for your aquarium, and the procedure on DIY instructions.
Good Luck

Answer 3

CO2 is one of the requirements for life for plants, just like we need oxygen, they need CO2. It's not dangerous at all and in fact is in your tank now, just not enough of it probably. If you have many plants, proper lighting and are fertilizing the missing link is most likely CO2. Here's two links that show some good designs for DIY or homemade CO2 equipment that is cheap and works well.

A basic intro to CO2 in a planted tank:
http://www.drsfostersmith.com/pic/article.cfm?aid=765

A basic DIY CO2 production system:
http://www.thekrib.com/Plants/CO2/co2-narten.html

A basic CO2 reactor for inside the tank:
http://www.plantedtank.net/articles/DIY-CO2-Reactor/2/

The only potential danger is injecting so much CO2 that is would harm your fish. That's a real long shot though and not really a problem with plenty of plants.
Hope this helps

MM

Answer 4

you must not put anything externally as it can be risky . but u must put equal number of fishes and plants to maintain the balance and so that the chain goes on but if u remove any one of this it can be harmful .....................