Seedling woes... Transplanted around 11 days. Day 26 now.

I'm a first time grower and I was just wondering if I could get some advice. I'm growing these 4 in a Space Bucket fitted with a 180w UFO LED and a 5m strip of 5050 LEDs. Earlier on I had some trouble with my soil being too hot for my seedlings and they started turning purple around the edges. I had to do an emergency transplant and they bounced back pretty well but now I am starting to notice yellowing and some darker spots on the leaves and edges of the leaves. The leaves are also rather droopy. Could somebody please tell me whats going on? I don't think I am overwatering. I am watering every 3-4 days when the soil is quite dry and I'm using a very, very weak liquid nutrient on it. (Yates Thrive.) Any advice would be hugely appreciated. Thanks!

PICTURES:
http://imgur.com/a/Ywe4E

Your leaves have that "over-watered" look which can also be lack of oxygen in your root zone. Given the look of your mix I can't imagine it is a lack of oxygen in your root zone which means to me there might be a problem with the health of your roots?

The plants also look underfed from the color so getting them a well balanced feed may help a lot. I'm not familiar with what is in the Yates Thrive. If it is well balanced then you need to check you ph levels. Hope these ideas help.

NPK of 12-2-6? Low on P if that's the case.

Too much water as well if you ask me. Mine are in similar sized pots (but slightly smaller plant) and get watered to light run off once a week. I've one droopy plant, but that's because it didn't take to it's first nute feed at all. The others loved it.

It may be overwatering although I didn't think I was doing too badly with that.

The nutes I'm using:
Yates Thrive ( http://www.yates.com.au/products/fertilising/water-soluble/thrive-soluble-all-purpose-plant-food/ )
NPK – 25 : 5 : 8.8 (using a half strength mix)

If I just back off the watering for a bit should I see an improvement in it? pH of my water with nutes added is around 6.5 - 6.6. I feel like my soil mix is fairly light too.

Since I took those pictures they look even more droopy and discoloured. I'm pretty worried.
Check it:
http://i.imgur.com/Vhzl2UX.jpg

Any other advice please? HELP!

buuuump

Stick to watering once a week until light run off for a while and see what happens. You're nute is heavy N which is good, but perhaps too heavy?? Not sure.