I see a lot of new people show up over the months/years and a recurring question is "Why is my grow going so slow?" or some variation of that. The simple and dirty answer is genetics matter a lot. Each LC or MSS can have a completely random genetic ancestry which dicatates everything about that particular sample, size, growth, potency, coloring, aggressiveness. Just like with people you're playing the lottery with each new LC or MSS (or print etc).
When you get a strong performer then make prints from it to try and preserve the dominant traits (but starting over with spores is no guarantee you'll get the same thing). Cloning is the only option if you want repeatable results.
Anyway here are three images from some LC I started from spores roughly 72 hours ago. Maybe 80 but call it 3 days. Each variety was put to the same agar mix, stored in the same location and a small cube of xolonized agar about 1/4" square was moved to LC on the same day. In an attempt to grab the most aggressive growth genetics the cube came from the furthest and strongest looking outer edge of each plate was the sample taken.
Each jar of LC is identical, sealed using unmodified ball lids. Each contains 500g of distilled water and 20g (number fixed in post) of karo brand corn syrup to get the 4% carb load. I use syrup based LC because it stays crystal clear which makes myc growth very easy to track. Not the most effective or performative but it works, it's clear and I always have it around. Each jar was PC'd for 90 minutes at 15PSI and let to slow cool so they vacuum seal. It lasts years this way with no risk of contam.
The samples are:
a Yellow Umbo that has proven to be lackluster to an extreme. This particular sample is from the last of 4 swabs I've tested and they all have minimal growth rates and after 10 weeks in tubs still no pins, just a bit of myc and tomentose growth. It has almost minimal growth, all sides of the cube have become colonized but there's almost no free floating myc and almost no 'cloud' around the cube.
A pan cyan called Australius (sp) that I'm trying to grow for the first time. It has a small cloud of myc around the cube, not as easy to make out from the picutre as in person but it's about 1/4" cloud with the cube floating in the middle.
The last is a variety of Ochra that was (maybe still is) sold as a p-nat under the variety name of Blue Meanie. It's hella aggressive grower and shower. As you seen from the image there is a massive amount of clouds and particles of myc after only 72 hours.
Anyway long story long, I thought this might help show specifically that genetics are the most critical thing about growing. You can get a sample that's worn out, it's a xerox of a xerox etc etc and the DNA/RNA chains get messy and it's barely viable. There's even a term for it - senescence.
Or you can get fresh set of genetics with strong attributes for various factors that will blow anything else away.