Very very slow growth

So my Plant 4 week is growing very slow. At the moment I am running a 75w LED which is atleast what Amazon said and its about 25cm away from the plant. The soil has a bit of perlite but otherwise its normal pot soil. The first time I ever watered the plant, I did way to much but since then I have been letting it dry and now the first 2-3 inches or soil are dry. I havent fed it any nutriens yet. The light scheduled is arount 15 light 9 dark. And there are fungus gnats larvaes in the dirt.
If anyone knows why please reply
Thanks!

What are your temps ? .... cold days and nights slow growth to a crawl.
Overwater conditions often bring bugs. That light sadly will not be of much use to you.

growing temps are around 24-26 °C all day and night. What lighting do you recommend ?

For now you can do better with a simple CFL ( moved close ) until you see light options.
This will do much better than that panel ... live it or not.


Those led panels like yours are all hype and no substance .... Look into quantum boards , CMH or other for some ideas.
This way if you are serious about growing ... Horticulture lighting group @Stephenj37826 can guide you to some great options based on what size grow you plan.

This a single QB quantum board running at a true 80 watts from wall growing solo cup seedlings ...
A single quantum can be powered to run a 2x2 space easily from seed to harvest. ( and can be powered up to 150w by dimmer knob ).

Thank you for your help

That light is perfect nothing wrong with it..I have 4 of them for vegging.