WyldFya;2228478; said:
Your fish will produce sufficient co2 for amazon swords. Don't worry about adding it.
This is great advice, go with it and you will be fine. Yes, the swords will not grow as fast... but that's a hit you take with low tech, and swords in the most part, for that matter.
In regards to Caoboy, they were talking about Flourish excel, which is a stable liquid form of gluteraldehyde. As every good science geek knows, aldehydes are just a member of the carbonyl group. Without going into too much, look at the root word. Plants can utilize this and break it down to plain carbon which they can use for growth. My suggestion is order it off Dr. Fosters Smith, you can get 2L (a lot for your use) for pretty cheap.
Going this route will give you slightly boosted growth, but at an extra cost. You have to weigh how simple you want to keep this. To answer your original question, you need nothing but can benefit from this product.
If you want to get real fancy you can hook up a $10 aqualifter pump to a 5g bucket in which you made a diluted mixture excel and water, then hook the power cord up to a lamp timer. Since the tubing for the lift pump is the same as an air pump you can slightly reduce the flow with a thumb valve (like 10 cents at petsmart) for airpumps. When the timer goes to "on", the pump turns on and spits out the diluted excel until it goes "off". I've done this before and, while it takes some trial and error, works fairly well for simple, set and forget solutions.
