2HR Aquarist APT Jazz

APT Jazz

APT Jazzis a root-tab capsule that feeds your plants from the substrate up. Tucked beneath the root zone, each capsule slowly releases a potent, aquatic-specific blend of nitrogen, phosphorus, potassium, magnesium, and trace elements — effectively giving tired, depleted aquasoil the punch of fresh soil again. Unlike many root tabs adapted from terrestrial “osmocote”-style fertilizers, Jazz is engineered from the ground up for aquariums, so it won’t throw the dangerous ammonia spikes that can trigger algae or harm livestock and delicate tissue-culture plants.

At Cuboid, the APT range is what we run in our own aquascaping display tanks — products we use ourselves day in and day out, and recommend without hesitation to anyone serious about a planted aquarium.

Why It’s Different:2HR calls it “the best root fertiliser for planted tanks,” and its real trick is keeping potent ammoniacal nitrogen locked in the root zone instead of leaching into the water. That’s the key tonitrate limitation— feeding nitrogen through the roots while keeping water-column nitrates low — the technique behind the deepest reds in plants likeRotala rotundifolia. Because of that slow-release mechanism, it works even in inert substrates like sand or gravel, not just aquasoil.

Used alongside an APT liquid fertilizer, Jazz rounds out a complete feeding strategy: liquids feed the leaves through the water column while Jazz feeds the roots from below. The result is thicker, fuller growth and stronger color, with a boost that endures for about two months rather than fading after a few weeks. After placing capsules, change water the 2HR way to clear any stirred-up detritus, and watch for the difference in new leaves within a week.

Dosing Guidelines:Place capsules in the substrate at least an inch (about 3 cm) deep, directly under the plants you want to feed — roughlyone capsule per 2.5 square inchesof planted area, or under each bush or stem cluster. For a heavily planted layout, 2HR suggests up to about 10 capsules per 8 gallons of tank volume. Replenish roughly every two months as the slow-release nutrients are used up.