First grow are my plants an ok size?

Hey guy my first grow here my plants are 5 weeks from seed, and I'm just worried they are a bit small for age?

My setup is a air cooled hood 600w hps dimmable which I'm running at 400w atm, 4 inch carbon filter kit 2 fans and a humidifier in a 2x4 tent. 5 inch fan for the hood.

I was running at 250w in a reflector before I got the hood a week ago.

I have 4 super critical plants in 3 gallon pots, using biobizz all mix and biobizz nutes, I have done some light pruning of big fan leave in way of tops, topping and lst as I'm planning on doing scrog.

I believe I had a magnesium issue, the waters very soft where I live, so started giving a small amount of cal mag and folier spraying with epsom salt every few days, seems to have sorted it

I do have some issues with heat atm but trying to sort them just very warm here just now.

But anyway what do you guys think would you be happy atm?

Pics?

They are around 15 inches tall

They look good!
Well done for your first grow and welcome to RIU.

Thanks man, I'm loving my girls. Find myself sitting just looking at them, trying hard not to micro manage them.

Just gave them some ecothrive biosys and charge as I want a little boost, want to start scroging soon, hoping to flip at the end of the month