Seachem Stability Market Report: Sales Volume, Market Share, Leading Brands & Market Trends

Seachem is the best-performing seachem stability brand in July 2026, moving 25,000 units across 5 ASINs for 53.2% of Top 10 volume. API follows with 20,000 units (42.6%), ahead of Fluval on 2,000 units (4.3%).

With 3 brands splitting the Top 10 and 100.0% of volume sitting with three of them, this is a concentrated shelf — the leaders hold multiple listings or one very high-velocity ASIN, so a new entrant competes against established review moats rather than an open field. Average selling prices among the leaders run from $11.38 to $14.99, which frames the price band a competing listing has to justify.

Based on July 2026 data, this shortlist surfaces the two kinds of ASIN worth keeping an eye on — the ones that just broke into the Top 10, and the ones growing fastest month over month. Specifically, one ASIN forced its way in: B006YG1ZLC booked 2K units at $8.68, with ▲ 0.0% MoM change. On the growth side, B0017JFX3C leads positive momentum with ▲ 500.0% MoM growth on 300 units, with B00FOW79US close behind at ▲ 150.0% MoM on 500 units.

The two signals carry different weight. A fresh entrant means share has already changed hands — an incumbent gave up its place to make room, so any competitive set drawn up a month ago is now out of date. A steep growth rate works as the earlier warning: it marks demand that is still compounding, usually a month or two before the ranking catches up to it.