Seachem Prime for guppies: choose the water being treated

Choose the application first

Seachem distinguishes separately prepared replacement water from direct aquarium additions. Read the reviewed Prime volume guide for the standard reference and that distinction; it applies to the calculation rather than selecting a species multiplier.

Check your volume assumption

A keeper records 36 L of actual water in a tank sold as 45 L. Enter 36 L as measured water. Do not deduct the decor again.

List adults, fry and any other residents before choosing a treatment setup. A guide about guppies does not establish compatibility for every animal sharing the water.

For a separate replacement-water batch, record that batch amount rather than copying the display tank's capacity. The calculation history should say which volume was used and why.

Check the result before measuring

1. Open the Prime calculator and select the application you intend.
2. Check units and whether the water amount is measured or estimated.
3. Measure the displayed quantity with suitable equipment.
4. Record the amount actually used, the time and other products in the system.

A conditioner result is not a diagnosis

This guide does not select an emergency amount from a test reading, prescribe a repeat interval or promise relief for an unwell fish. Read the separate Prime emergency and test-limitations guide when that is the issue. Do not use a higher routine dose just because a tank is heavily stocked, contains goldfish or has a small treatment vessel.

Check a medicine's own conditioner restrictions before combining products. A correct Prime calculation does not establish that combination's suitability.

Sources and review scope

Seachem Prime directions. Reviewed 28 October 2026. Published manufacturer directions and editorial claims; not an independent clinical or efficacy assessment.