DrKong said:I use those mosquito bits that have a predatory bacteria in them. They keep the fungus gnats away for sure. I use soil so they might not work as well in coco. They make a liquid form which works better/costs more called Gnatrol. same bacteria.
You might like to recalculate. Gnatrol is much less expensive on a gram for gram basis of the active ingredient.
BTI at Lowe's in the form of mosquito dunks @ about 10% BTI = .275 ounces of BTI per package at ~$10 = $36.30 per ounce.
I purchased a 2.5 gallon of Gnatrol for a little less than $150 delivered. It's about 6%, giving you 19.2 ounces of BTI @ $7.81 per ounce.
quick pop quiz: which weighs more, a fluid ounce or a dry ounce. Ring the game show buzzer if you think they weigh the same.
Gnatrol is much much cheaper by weight than mosquito dunks.