Brightwell SpongExcel — ionic silica solution for sponge and gastropod growth

The Brightwell SpongExcel is an ionic silica solution designed to boost growth of sponges and gastropods in marine systems short on silica. Formulated by a marine scientist at Brightwell Aquatics in the United States, it supplies bio-available silicon needed for siliceous skeletal structures (sponge spicules) and mollusk radulae.

The product is especially useful in aquariums holding spongivorous fish — marine angelfishes, butterflyfishes, and allies — that continuously graze sponges and require fast sponge-population growth to stay in natural food.

What SpongExcel is for and when to use it

Aquariums with spongivorous fish — accelerating sponge growth to keep angels and butterflies on their natural diet.
Sumps with filter sponges — silica supply to strengthen spicules and colony structure.
Reef gastropods — cerith, nassarius, trochus that produce siliceous structures.
Silica-limited systems — tanks on pure RO/DI where SiO₂ is absent, a state that caps siliceous filter feeder growth.

Brightwell official use

Ratio: 1 drop per US gal (3.8 L) raises ionic silica concentration by approximately 0.20 ppm.
Dose gradually while watching the target concentration.
Targeted use: silica-limited systems where sponge or gastropod growth is slowed by SiO₂ scarcity.

Caution: SpongExcel and diatoms

Ionic silica also feeds diatoms — brown algae that typically bloom in young silica-rich tanks. Dose sparingly, and only when sponges or gastropods actually justify the input; on a tank where diatoms come back regularly, SpongExcel can worsen the issue.

Specifications

Brand: Brightwell Aquatics (made in the USA)
Available sizes: 60 mL, 125 mL, 1 L, 20 L
Type: ionic silica solution
Target: sponges, gastropods, siliceous filter feeders
Audience: aquarists with spongivores or sponge colonies to support

Why choose Brightwell at ReefSolution

Brightwell AngeLixir — the food enricher for spongivorous angels and butterflies, complementary to SpongExcel which supports their natural food.
Brightwell MicroBacter7 — the bioculture that helps control the nutrient excess a high silica dose might bring.
Salifert Silicate Test Kit — the 0.15 ppm titration kit required to steer silica concentration without triggering a diatom bloom.

Frequently asked questions

How much silica does 1 drop of SpongExcel add?

Brightwell publishes an exact ratio: 1 drop per US gal raises ionic silica by approximately 0.20 ppm. On a 100 US gal tank, 100 drops (about 5 mL) therefore add 0.20 ppm SiO₂ — a dose to repeat based on uptake by sponges and gastropods.

Does SpongExcel cause diatom blooms?

Ionic silica is an essential nutrient for diatoms. On a tank where diatoms are already present or come back regularly, SpongExcel can worsen the issue. Reserve its use to systems actually short on silica where sponges or gastropods justify the input, and test silicate concentration regularly.

Can SpongExcel be dosed on a tank without sponges?

Little point — with no sponges or silica-consuming gastropods, added SiO₂ feeds diatoms and nuisances. Brightwell positions the product specifically for tanks holding siliceous filter feeders.

What silica concentration should I target in a marine aquarium?

Brightwell does not publish an explicit target range on the product page. Reef practice generally considers silica below 0.5 ppm as safe. Use Salifert Silicate Test Kit to steer dosing without going past that range.