Super Iced Grapefruit Auto - First grow - problems?

I have some SIG auto plants on the go they are from seed and seemed to be doing quite well but this last week once of the plants look pretty unwell, leaves are droopy and growth is stunted and tips of new growth looks yellowed or burned.

Also they seem to be very small and very bushy and not stretching up at all.

Im using a 600w hps in a 90x90 tent for both veg and flower in same space, temps are running 75-80 light on and 60-65 light off on a 20/4 cycle
they are being grown in a mixture of regular potting soil, miracle grow compost, perlite and vermiculite and im using bio bizz nutes grow/bloom to 1ml per 1 litre of water mixture on every 3rd watering

here are some picturesthis is the sick plant that seems to be struggling, i just flushed her today to see if that helps



and here is a more healthy looking specimen



these plants are both 4 weeks old from sprout any help with the sick plant would be great and also how does the healthy plant look? shes really small but shes just so bushy


thanks folks

You need to do some lst. And how often are you watering? The sick plant has Nute burn and over or under watering. Pull them apart tie a string to the stems under the closest node from the top and pull it down and tape it to the side of the pot. You can just pull a leaf down and tape it too.

Where did you get this strain in auto form?????

Im just watering when the soil feels dry again, but i may have watered a little early since moving them to there bigger pots?

the plant that isnt sick does it look like its a good size for 4 weeks or is that stunted too?

rizz, now im doubting myself.... was this an auto? im sure it was auto fem on packet but i cant find where ive put it lol

Im pretty sure that it is a fem photoperiod plant. I would love it if they came out with an auto.

looks like an auto thats for sure. The sick plant looks first and foremost heat stunted...so jut make sure lights arent too close. Other than that it looks overwatered, so try judgin your waterings by the weight of the pot rather than the first inch of soil coz that isnt always accurate. Does not look like nute burn, but you dont need to be adding ANY bloom nutes until you got flowers popping up all over the place or else those nutes will just accumulate and cause lock-out. You can't force feed a plant it eats as much as it can, and ur plants auint even flowering yet. But the second plant looks healthier. GL and keep updated

does anyone have an idea of what a might yield from this? i have 3 plants growing currently 2 of which are healthy and one a little sick, seed company states 600gr/m2? seems a big yield to me, i was hoping for about 2oz per plant? would that be fair to assume under a 600w hps?