Agralan Fungus Gnat Control

Fungus Gnats (sciarid flies) Nematodes for House Pots & Seed Trays, Makes up to 5 Litres. 

Control of Fungus Gnat 

Fungus Gnats although harmless to mature plants, they are regarded as a nuisance pest, the larvae may cause damage to the roots of seedlings. The flies will be found around damp soil or compost which will play host to the larvae.
The parasitic nematode, Steinernema feltiae, can be used as a non-chemical means of control.
  
Soil temperature must be at least 12 °c

How to treat
It is vital to apply to a moist soil as the nematodes are unable to move in dry soils.

2.5 million pack: Mix the entire pack of nematodes in 5 litres of clean water, apply immediately using a watering can using the spout, or the can fitted with a coarse rose (2mm).

Storage
The unopened pack may be stored in a fridge but must be used by the expiry date on pack.  Do not freeze.  Once opened, the entire pack contents should be used immediately.