Seandgoode said:
Just a thought, will adding liquid carbon effect cycling my tank in any way? I haven't used any yet but I'm guessing I will have to add some form of carbon with 3 plants.
It depends on the plants... Some plants are slow growers and require very little to be content to grow (albeit slowly). Other require high light. High light plants generally require carbon additions.
There's two schools of thought for cycling and plants (well, probably three or more, but I'm going to limit it to two):
School 1 - Cycle the tank before you add plants... so few plants would change much in terms of how the cycle takes place, so the easiest thing to do would be just to wait on the addition of plants and add them at the end of the cycle.
School 2 - Add plants at the beginning of the cycle. This can end up changing everything. There are a lot of variables to be considered in this and more information is required. 3 plants won't be enough to 'cycle' the tank by themselves (most plants can use ammonium in the tank, rather than nitrate, if the ammonium is available). But, adding 3ppm ammonia could potentially harm the plants as that ammonia won't be used or processed by the bacteria very quickly. So, if you absolutely have to cycle with the plants, I'd drop the dose of ammonia to only 1 ppm and test daily to see what happens to the ammonia. Does the ammonia get used by the plants - and therefore you don't see nitrite building up? Or does the ammonia get converted to nitrite by the bacteria? More than likely you'd have a very slow process of the initial ammonia dose dropping to zero (or at least under 0.25ppm)... once it does you'd want to up the ammonia back to 1ppm and wait again, looking for nitrite. If nitrite never shows up, then the plants are using the ammonia (more than likely won't be the case with just three plants). The slow build up of nitrite will be evidence that you are growing a bacteria colony. Not until you get both to be double zeros would it be safe for fish... and with such a low dose of ammonia, you'd want to stock the tank very slowly.
As to the actual question being asked... I have not heard of glutaraldehyde affecting the cycle either pro or con. I do know that it doesn't have an appreciable effect on the bacteria colony (when used in proper doses) once it is established, but as Daize points out, it might affect the bacteria as they try to establish their colony.