Is medium too compact?

[CollegeKush]

Hey guys and gals, I just have a question about my soils density, I have 2 sour jack sativas going (about 3 weeks into veg) and I'm using a top soil and cow manure mix. They seem to be looking good but growing slow and I was wondering if it's because there's not enough oxygen getting to the roots because there's no perlite in the mix, if so please provide me with a solution. Let me know what you think (they are the larger plants in the photo).

 

[Jackalope]

Looks like there is vermiculite in there. It does the same as perlite. Hard to tell about density though. Looks like all your plants on in that slow period after germinating. They should take off any day now. It takes a bit for starts to build a good root system and really take off.

 

[TorturedSoul]

there's no perlite in the mix

Cannabis plants don't seem to thrive in mud, lol. I like perlite because it's neutral, lightweight - easy to carry four-cubic foot bags of the stuff - and reusable (although I mostly just recycle growing mixes into the food garden). I tend to use about 25% perlite in my soil mix.

Looks like there is vermiculite in there. It does the same as perlite.

NO, it does not! Perlite is for drainage and encouraging better root aeration. Vermiculite, OtOH, increases the water-holding (retention) ability of the soil. Vermiculite can also be of a non-neutral pH (alkaline, IIRC), depending on where it was sourced from.

I used to use vermiculite (not as a perlite substitute, though). But a little bit slowly became a very little bit and - finally - none. There's about 75% of a two-cubic foot bag of the stuff left out in the shed; I think I bought that bag six years ago, lol. Perlite... I go through perlite. What I don't use ends up in Mom's container plants when she invites me over to mess with them. And, eventually, it ends up in one of our in-ground gardens to help lighten the heavy soil (I'm not a fan of adding sand).

 

[CollegeKush]

Great info thanks guys!