Water problem

Well, interesting! I'm assuming you've grown in coco before and know that it must be kept moist at all times, yes? And if the seedlings were lying flat on the coco, it was probably because they weren't getting the water they needed... and knowing how quickly the roots grow and how long they get, they're probably now down at the bottom of that 5 gallon pot and happy because they're in moisture... But that being said, the fabric itself should not be wet (damp is fine, wet is not). I would construct a rack of some sort to keep the pot slightly off the ground so you can give it good waterings/feedings with runoff but so they are not sitting in water all the time. Good drainage is a must! As for the 5 gallon pots - when I grew in soil (I only grow in DWC now), I would start all my seeds in the pots they were going to finish in since all I grow are autoflowers... and the 5 gallon pots were never a problem. If you're growing photos and you feel they ARE a problem (the pots), then by all means, transplant them into a smaller pot and go from there... but the Sweet Cheese sounds like it might be an autoflower (?) and they don't like to be transplanted so I'd leave her alone. Just keep your coco moist and give her good nutes... I wouldn't give just the Big Bloom, I'd also be giving some Grow Big, particularly for the stage they're in - but watch it... I've used FF nutes before and always had a problem with the Grow Big causing nitrogen toxicities and it drove me mad... so go lightly with it at first... you can always increase the dose if needed but it's easier to treat a deficiency rather than a toxicity. Good luck!