Activated Carbon And Plant Ferts

[stanleo]

I have read books and a lot of posts on here about plants in the aquarium but I don't remember coming across this. When you are dosing plant fertilizers like iron, potassium and the micros should you or should you not use activated carbon in your filters? I just set the tank up and I had to dose Melafix for a week so I put in carbon to take the medication out after the treatment. Should I leave the carbon or take it out? My plant fertilizers are coming in the morning.

 

[KirkyArcher]

No need to use carbon in a planted tank, yes it will absorb a substantial amount of the ferts, until it becomes saturated and can't absorb any more, also no need to try and chemically remove melafix or primafix  

 

[Zikofski]

yes you should take it out use it for a few days to a week to remove tbe chemicas you added from the medication after that just take it out and replace with filter floss

 

[Stu4648]

I keep the carbon in mine and just turn my filter off for 4 or 5 hours after dosing to give the plants some time to uptake at least some of the nutrients. Probably is not enough time but they are still green and growing well, in some cases propagating themselves too well so I guess it must be enough. During the time the main filter is off I have a small, foam cartridge only, filter running and a wave maker going to keep the water moving.
 
Gives you an option if you want to keep using carbon, although as the guys above say you probably do not need it in a heavily planted tank. Not sure why I continue to use it but I am too lazy to remove it when I dose my plants once a week so came up with this compromise.

 

[Byron]

I would not recommend carbon in planted tanks, for the reasons already mentioned.  Along with certain mineral nutrients, carbon is also effective at removing DOC (dissolved organic carbon) and this is obviusly an essential nutrient for plants.  CO2 is usually the one nutrient in limited supply, so nothing should be done in the way of filtration to lessen it further.
 
Having said that, it is true that carbon does lose its effectiveness as it adsorbs (this is adsorb, not absorb) things.  The time taken to reach this point varies depending upon the conditions in the individual aquarium.  But for example in Stu4648's situation it may well be that the carbon is no longer effective so at this point it is simply normal bio media.
 
When we add live plants to an aquarium, we need to remember that they are the best filtration, and if they are allowed to just do the job, things should be fine.  Of course, this assumes a balanced system (fish, plants, tank volume, etc).  After all, one can have a healthy planted tank with fish and no filter at all; I've done this with no problems.  The less we interfere with nature, the more stable things will likely remain.
 
Byron.