seeds MG seed starter. WTH?

[fishhead]

So, I'm running another trial or two for "Science is Fun", and I'm messing around with a few soil types.  One thing in my current stable for growing is Miracle Grow (MG) Seed Starter. I've used it for years with other veggies with what I thought was decent success.  I have sprouted a few seeds in it this winter.  I have transplanted a few coffee filter/baggie sprouts into it this winter. I have some decent plants growing in it under lights right now.  I have had some damping off and an alarming rate of helmet heads.  But, all in all, things have been going ok.  
 
Until now.  Like I said, trying some soil types out for germ rates and transplanting.  And for a couple of upcoming trials unrelated.  This trial I'm using 4 soils. A) Vermiculite, B) 50/50 Vermiculite/Perlite, C) 50/50 Vermiculite/MG, D) 100% Miracle Grow.   6 Small vials per soil, 2 Thai seeds per vial, exact same volume of soil, exact same water and humidity, exact same light, exact same temperature.  Everything is gonna be tossed at the end of this, and the trial is still ongoing
Also, I did 2 small cups with only MG and the 50/50 Verm/Perm and 20 seeds each (my leftovers).
 
Well, the trial is still ongoing, so I'm not going to go too much into detail, but A and B are doing ok, but C and D only have one sprout for the 24 seeds.
On top of that, those two leftover cups, the verm/perm has 19 of 20 sprouts, and the MG has exactly 1 puny one (half the size of the verm/perm sprouts).
 
So, my question to all of you sages and soil scientists out there is - WTH is going on with MG seed starter mix and pepper seeds? Is it just peppers, and is it just germinating seeds?  Cause my growing plants seem to like it, but the babies - not so much.  

 

[CaneDog]

I've have perfectly good results germinating with MG seed starter.  If I were having trouble with it, I'd first consider whether it was holding too much water thus the seeds weren't getting enough oxygen. When I look at what did well for you versus what didn't, your mixes with lower water retention/greater aeration (due to granularity) are doing better than those that hold more water/less oxygen.  That may mean over-watering for the specific medium or perhaps the watering is fine, but the lower aeration is just slowing them down a little relative to the others.
 
I'm impressed with the solid numbers you're getting from A and B.  Are the seed coats coming off of those well?

 

[fishhead]

Hey CD,
Yep, I'm with you. It does seem awfully easy to make the MG soggy. Then, drying takes some time. The small vials with any of the medium are definitely not soggy by now. It has bee 10 days since planting, but the MG vials are not doing much compared to the others. I've read multiple times here on THP of MG being "death" for germinating, but didn't think much of it. I thought all was going ok for me, and the I saw this happen, and then had second thoughts.

Zero helmets for the A or B. All look great.

If nothing else, it gives me a good baseline when doing other trials. We'll see.

BTW CD, pubes are germing and sprouting great, except for the Turbos. Not much luck so far. Will stay at it....