Oceans blend to "hot" for seedlings?

So to start things off, generally speaking, when I grow indoors I usually let my seedlings germ and place them into cups with coco noir. I leave them in there with next to no nutes for about a week, then I transplant elsewhere. However, right now I have 5 seedlings that I alive and well inside small cups of FF oceans blend. They all pretty much sprouted and germed inside the soil.

Anyhow, the past 2 days I've had 2-3 seedlings dry up and die on me. At first I thought it was a heat issue, but I'm literally running only ~40 watts on the seedlings themselves, which doesn't seem like an issue to me. So now I'm thinking maybe the FF soil burned them? I haven't added any nutes to the guys, yet I feel something has to be to blame for the two of them dying.

Also the ones that did dry up and shrivel over, they seem un-revivable. I don't know if I could ever bring them back to good health at this rate. I'm worried some of the other little guys might end up doing the same thing.

Is FF Ocean's Blend too much for seedlings?

I've never used ff, but i've read a bunch of people say they have nutes already mixed in it, which is a no no for seedling. I'd try to get all of them out of the ff , and use some pro-mix.

Yes, FFOF is loaded with nutes bro. If you're going to use it for seedlings mix it as a 50/50 ratio with another blend of no nutes.

i have bagseed planted str8 into a party cup with ff, and mg mix and its looking good sooo far, so i dnt think your theory is on point....

I have started dozens of seeds in FFOF with no problems.

i've waited around 2 weaks or so b4 i transplant into the HOT soil...

never had a problem

I use FFOF and Lightwarrior 50/50 and never had an issue from seedlings...
just switched to Roots 707 and germed in there no probs either... IMHO FFOF holds water so you need to cut it down with something like was previously suggested, use perlite coir etc..