Thank you and that is correct, there is air in the black pipe, and when using a 2in fill tube, I believe it allows fresh air to get inside the pipe, especially while filling. It's been working nicely for me, no complaints so far.
I close off both ends of the pipe with chz cloth and zip ties. But upon dissecting the last one, I noticed the chz cloth was gone. I don't know where it went, but I couldn't find it. I guess its possible the em1 dissolved it or I dont know, but the pipes were mostly empty regardless so I'm continuing to do it this way. I haven't noticed any bad effects and it seems to do what its intended for regardless of where the chz cloth went.
Awesome, thanks for the reply!
Just digging a bit further...
If you have the ends sealed with cheesecloth, then the black pipe would be full of water or at least till the drain height.
Very interesting that there is no physical air gap and it is working so well!
I would imagine that the micro-organisms used the cheesecloth as a food source since it is a natural fiber.
Very keen to try your techniques out on my next grow, although I will start with a more traditional SIP in 5 gallon buckets and see how that goes.
Hopefully after that grow I will try this newer technique of yours!
Have you used the Step-Well soil? I tried it last grow with fabric pots and Autoflowers and was not too impressed.
Will continue using the EM1 in the SIP's though.
Still going through all your posts to get as much info as possible!