Re: Fluval canisters - how is yours set up?
I like loading canisters with bioballs, plastic pot scrubbers, or Seachem matrix. If I had money I'd do only Ehiem substratpro. IMO, cheapest and the biggest bang for its buck is plastic pot scrubbers. $1 for 6 is hard to beat.
Carbon is practically useless unless you're trying to take meds out of the water. If you're using it as a water polisher, do yourself a favor and pick up some purigen, you'll be amazed. Also, if carbon sits in the tank too long, it can start to leech out whatever it soaked in. And as someone mentioned already, it'll take in nutrients the plants can use. Purigen won't leech what it soaks up and you can recharge it instead of having to buy more. Purigen also polishes the water much better.
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