About Stock

Most people's first wavemaker is a small propeller pump stuck to the glass with a magnet, pushing a jet of water in one direction. That's a point source. A gyre-style unit works differently. Instead of a narrow jet, it uses a wide, thin impeller housed in a long chamber to move a broad sheet of water across the tank, more like a river current than a fire hose.Point-source pumps vs gyre flowA standard propeller pump moves a lot of water through a small cross-section. That creates strong localised current with dead zones everywhere else, unless you run several pumps and...

Every reef tank loses pure water to the air constantly. Salt does not evaporate, only water does, so as the level drops the salinity of what remains slowly climbs. Left unchecked for even a day or two in a warm Brisbane room, that drift can push specific gravity up enough to stress coral tissue and throw off dosing calculations that assume a stable volume. An ATO exists to solve exactly this one problem: replace evaporated freshwater automatically, before it becomes a swing.Manual top-off works fine for some keepers, but it means topping up at the same time every day without...

A lot of coral and fish feeding failures come down to one simple mismatch: the food is the wrong size or shape for the mouth it is meant to feed. A large-polyp coral will happily grab a chunk of mysis. A small-polyp SPS colony cannot. A powerful reef fish will inhale flake in a heartbeat, but a shy mandarin needs something tiny and slow moving. Getting particle size right is the difference between food that actually gets eaten and food that just dissolves into your water column, feeding algae instead of your animals.Start with the mouth, not the bagBefore buying...

Every hard coral in a reef tank is quietly pulling calcium, carbonate and magnesium out of the water to build its skeleton. In a wild reef that supply is endless. In a glass box it runs out, and when it does, growth stalls, tissue recedes at the base, and polyps stop extending properly. Supplement dosing is simply the job of replacing what the corals removed, at roughly the rate they removed it.The three-part conceptCalcium, alkalinity and magnesium are usually talked about as a trio because they interact chemically. Alkalinity (measured as dKH) is the water's buffering capacity and its supply...

Every reef and planted tank grows a film of algae or biofilm on the glass within days of a water change. Scraping it off without scratching the pane is one of those small jobs that separates a clear, photo-ready display from one with a permanent haze of hairline marks. Magnetic cleaners solve this by letting you drive a cleaning head on the inside of the glass using a handle on the outside, with no need to get your arm wet past the elbow.The part that actually touches the glass matters more than the magnet itself. There are three common head...