Salifert Marine Reef Test Kit – Silicate

Allows you to accurately test for levels of silicates in your aquarium, of which high levels can spell problems for your aquarium systems. Test today to avoid problems in the near future.

Silicate occurs especially in tap water or in purified water when the RO or DI unit is not functioning properly. Silicate not only results in diatom bloom but might also block some essential trace elements such as vanadium and molybdenum.

Salifert offers a very sensitive and accurate silicate test kit. Silicate content can be decreased by using the granular Phosphate-Killer or the liquid Phosphate-Eliminator. Although both are designed for phosphate removal they have also a very high affinity for silicate.

Approx. 60 tests per kit. The range is 0.03 – 30 ppm as SiO2.

How to Use

The silicate kit has two modes. The normal mode uses a 10 ml sample; the low-resolution mode uses 1 ml and half the reagent, and its readings are multiplied by 10.

Salifert’s procedure (low-resolution quantities in brackets):

1. Add 10 ml of water to the test vial with the syringe (low-resolution mode: 1 ml).
2. Add 4 drops of Si-1 (low-resolution: 2 drops) and swirl the vial gently for 10 seconds.
3. Let it stand for 5 minutes.
4. Add 4 drops of Si-2 (low-resolution: 2 drops) and swirl gently for 30 seconds.
5. Add 1 level scoop of Si-3 and swirl the vial for 20 seconds.
6. Stand the open vial on top of the colour chart, on a white part of the chart, and compare looking down from above. An intermediate colour means an intermediate value.

If you used low-resolution mode, multiply the chart value by 10.

Units. The chart is in ppm (mg/L) silicon dioxide. To convert to ppm dissolved silicon, multiply by 2.1. Range: 0.03 to 30 ppm as SiO₂.

Where the readings stop being reliable. Salifert warn that erroneous results can occur when carbonate hardness is above 20 dKH (an alkalinity of 7 meq/L). Normal aquarium water sits well below that.

What the numbers should be. Salifert’s guidance: do not use tap or RO water containing more than 2 ppm as dissolved silicon, and in marine water the dissolved silicon content should be below this test’s detection limit — on a reef tank, in other words, the right answer is nothing at all. Anything readable points at the RO/DI unit, and usually at an exhausted DI resin, because silicate is one of the first things to break through.

Two habits that make the readings repeatable: compare the colour in daylight or under a neutral white lamp rather than over the aquarium, where blue light shifts everything; and rinse the vial with RO water and shake it dry between tests, because reagent left in the vial is the single most common cause of a reading that will not reproduce.

Handling: Si-1 and Si-2 are acidic, and Si-3 contains a reducing agent. Gloves and eye protection are recommended, and this one is worth taking seriously.

Salifert’s cautions: keep out of the reach of children; for aquarium hobby use only, not for consumption. Salifert recommend protective gloves and eye protection. Read the leaflet in the box before the first test — it is the authoritative version, and it is what the colour chart is calibrated against.

What’s in the Box

Salifert do not publish a packing list. What the procedure uses, all supplied in the kit:

• A syringe, for the 10 ml or 1 ml sample
• The test vial
• Three reagents: Si-1 and Si-2, both dosed in drops, and Si-3, a powder
• The level scoop, for the Si-3 powder
• The colour chart, read from above
• The instruction leaflet

Three reagents and two timed waits make this the longest of the Salifert procedures — about six minutes of standing time per test. Worth knowing before you start it in the middle of a water change.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.