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soil Topping off soil with perlite?

I'm quite the rookie when it comes to growing chillies, and this forum is amazing for getting quick answers from experienced growers! 
 
I've recently started to grow chillies in a grow box (I know I am months too late..) and I was wondering if it serves a purpose to top off the soil with perlite, like a top layer. Even though I don't have any problems (yet) with mold or moss (I use a computer-fan to keep the air circulated)
 
Does it give me any benefits? They have already sprouted btw.
 
Cheers,
Ab
 
I tried this once thinking it would act as a mulch or similar.  It floated up when I watered and didn't let the soil  heat up so my soil stayed soggy under the layer.  I actually started to get algae between the layer of perlite and soil so I abandoned the idea.  Maybe others have had different experiences? 
 
I have experimented with perlite topping. It does help keep fungus gnats away, if that's a problem. It may also help reflect the light some. But, I find the negatives outweigh the positives. It takes a fair amount of perlite to top your plants in 5-7 gallon pots. Also, wind and waterings tend to scatter the top layer of perlite easily, making a mess. I would also dump perlite by accident when moving pots around. The perlite starts nice and white, but after time, turns brown from soil and watering, and green with algae even with good ventilation. I don't do it anymore. If I were to get a fungus gnat infestation, I try sand next time.
 
People often top their indoor pots with perlite, sand, or bark fines to help keep fungus gnats away, but its also usually accompanied with bottom watering.  It kind'a defeats the purpose if you water your plants from the top.
 
I like to use ultra fine bark to top my pots.  I sift bark mulch through a 1/8 inch mesh grate and use the bits that make it through to top my pots with about 1/2 inch of bark. 
 
Yep, perlite makes a pretty terrible mulch (speaking about outdoor application). Stick with traditional mulches; bark fines, compost, or even gravel, would all make better pot toppers than perlite.
It splashes out in the rain, blows away in the wind, gets funky looking, is expensive (compared to other mulch), etc.
However DO use it inside your soil mix where it can do its job!

Just my opinion of course :)
 
I have used perlite as a hopeful preventative for fungus gnats in my indoor grow and it failed imo. I removed a layer of old perlite only to find that it was giving the fungus gnats protection and keeping the soil moist for them to breed in. Plus there are so many air holes it basically just builds them a nest as far as I feel.
 
I have used sand (washed play sand from HD/lowes) and it seems to work a bit, but I would rather just work on my watering habits and have found it helps a bit. I also just do insecticide root drenches. 
 
That was my experience, short lived and only lasted one round of pots. Will not do again.
 
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