stunted growth

Idk whats wrong my plant sprouted just fine and grew good for the first week. Its chocoloco from vision I have it under a 400 watt mh dimmed to 50% im using gh flora series and a couple of drops of superthrive every couple weeks per gallon it is now 5 weeks old today and is only 4" tall and maybe 2" wide it has 5 nodes but the whole plant is small alltogether the stem looks like a seedling stem. The first set of true leaves are like a pale yellow to a almost white color and the rest of the leaves are a good green color idk whats wrong with it. Any help would be greatly appreciated I cant take any photos but if you have any other questions let me know im stumped here

Photo's are something that will always help when it comes to something like this

Can i ask how far the light is from the plants if the bottom leaves are yellowing this can mean too things she needs more food or you have given her to much food
and you have a lock out

Test the run off make sure what your feeding it is the same as what your giving it if your in soil don't over water as that will stunt it's grown

I recommend only using PH water listing what time of type what are you growing in coco soil ... the more info you give the more help we can give you could just have a runt sucks but they happen next time try not to feed till you have the first couple of true leaves or start very low

super thrive is very strong and a couple of drops is a lot when i used it i would put
one drop in 1 gallon of water

Its in mg soil I added permits so it's about 60% soil 40% perlite. The light is about 2' away. I didn't start adding mutes till the cotelyn leaves started turning yellow and I started 1/4 strength mutes. My ph is the same as when I water it and the ppm is actually lower than what I put in. And so far I had some cheese seeds from vision that did the same thing but they were in dwc so I switched back to soil and this chocoloco is doing the same as the cheese