The Aquaripure denitrate filter is a canister filled with 4 different densities of sponge material from coarse to very fine. Water flows through the filter at a very slow rate. Initially aerobic bacteria/Archae process ammonia and nitri
tes. As water moves slowly through the filter, the oxygen is depleted and anaerobic bacteria oxidizes the nitra
tes releasing nitrogen gas, completing the N2 process.
The oxygen is depleted in the dripping return water, however a basic mechanical filter water movement will resolve this. I think there would be little detriment to plants I could imagine...except the absence of nitrates in the water. There would likely be a reduction in dissolved organic compounds and perhaps some trace elements...I'm just not sure.
But the above, although an important primary function, is only part of what this filter really does. To a degree, there is advanced bio-filtration going on here unlike what we see in conventional filters. I believe many harmful compounds/chemicals are broken down in such a process.
(note: research bio-sand filters used in the 3rd world where foul, polluted water is poured in and crystal clear drinking water comes out.)
The alcohol or a sugar solution like grenadine is used to feed the bacteria to promote a much larger colony than would otherwise be the case.
In a moderate to heavily planted tank you probably won't have a nitrate problem because the plants will process the ammonia preventing nitrites and nitrates.
This filter would be a huge advantage in many SW tanks for fish and corals with a low tolerance for any nitrates in the water (not to mention the cost savings of reduced water changes from marine salt and RO/DI water).
If the challenge is high nitrates in the source water, there are also other options.
This may have value: http://www.tropicalfishkeeping.com/f...-water-156489/