It will make a five gallon bucket full of water boil with a good air pump. The nuts are for extra weight to keep them at the bottom of the buckets.
Great minds think alike.
Always brother, I like the dome idea dont get me wrong, but the line puts more surface area of air pumping in there and u cant coil it through the coco or soil better so all roots are really premuch right next to the line instead of just the bottom, compared my pics to other dome grows and had tons of roots around the whole chunk of coco not just a 1-2" layer at the bottom which is still great but imo even all those sucker and lil sugar roots throughout the top of your medium I think enjoy the air also, and I cold turn the air on as soon s they popped to help those starting fingers spread out, I still hand watered but I always watered the far outside 1" from the pot is where I would water an even 1" wide line around the square pot. Man I really wanna bring mine back out for battles.
Sorry, I guess I was trying to paint a picture rather than answer your question. I cannot say I have ever grabbed ahold of it just to see if I could feel the air coming out, so I cannot honestly answer your question. But I know that air comes out because I have ‘seen’ it.
I really don’t know if it helps or not and until someone does a massive side by side using a single cloned strain I will call it personal preference.
I know plenty on here that don’t use them, but the variables are too many for any scientific comparison. I have an air pump and it’s not being used so my pots will continue to have air injected. 
