I’ve got my tank set up and it’s currently cycling. However I’ve noticed in the filter compartment there’s space for some additional media or product of some kind. See photo below- I’ve circled the two sections of space. One is below the existing filter media, the other is below the skimmer.
Does any one have any suggestions what I could buy to put in here to aid my filtration? Ideally that won’t break the bank.
I’d be particularly interested in anything that has a good success rate of reducing nitrates.