Spider infestation in hydroton

[Benjamin Udy - Super Genius]

I am having a spider problem in the top layer of my media in my flood and drain grow bed. They are not spider mites, they are much larger. They are small black spiders about 1/8" - 1/4" in size. I can see little webs on the top layer of hydroton and a few random webs on some plants. I tried flooding the grow bed this morning high enough to submerge all the media and 100's of spiders came crawling out. Has anyone had this problem?

[Jonathan Kadish NYC AA Chair]

Picture?

[Benjamin Udy - Super Genius]

Jonathan Kadish NYC AA Chair said:

Picture?

[Benjamin Udy - Super Genius]

I have done a little searching online and it looks like the type of spiders that are inhabiting my media are called dwarfspiders (Erigoninae). There are many different types of dwarfspiders and due to their small size they can be nearly impossible to identify what the exact type is without a microscope. My question is are they going to effect my plant growth or anything else in the system?

[Jonathan Kadish NYC AA Chair]

Well looking at your pictures the water level is quite high which would attract other insects. The spiders are their because those insects are a good food source. I have a few different species of spiders and lady bugs around my indoor system hunting spider mites, aphids and fungus nats. These guys are probably doing you a favor.

[Benjamin Udy - Super Genius]

Thanks for the feedback Jonathan. I intentionally raised the water level past the stand pipe to evacuate the spiders from their nests in the media so I could snap some photos of them. The top couple of inches of gravel are normally dry. Do you think that the presence of them and their webs near he maristem of some of my plants is going to effect plant growth in any way?


Jonathan Kadish NYC AA Chair said:

Well looking at your pictures the water level is quite high which would attract other insects. The spiders are their because those insects are a good food source. I have a few different species of spiders and lady bugs around my indoor system hunting spider mites, aphids and fungus nats. These guys are probably doing you a favor.

[Jonathan Kadish NYC AA Chair]

I don't know if you will find an expert on that here, but plants should be able to break through webbing... maybe not a seedling. You will be the expert after this experience. I would imagine the population will drop as food runs out.

[Alex Veidel]

I've had spiders in my system forever; they're harmless.