My very first grow

Your grow looks like it's doing very well so I wouldn't worry, to be honest! If you ARE worried, you could transplant into a larger pot mixing in more perlite so loosen the soil up and provide good drainage. It DOES look like you've got quite a problem with fungus gnats. These pests live in very damp soil so you may be overwatering! They're easy to get rid of (and you should!)... get yourself some Mosquito Bits and follow the directions... essentially, you soak a certain amount of the granules in the water you're going to be using straining them out of the water after 30 minutes. This solved my problem with only one dose but a heavy infestation might require one or two more treatments (you only use this once a week as the package will tell you). You can pick some up on Amazon or in pretty much any garden center. As for nutes... your plants look very healthy - there's no sign of either toxicity or deficiency - so this is not something I would worry about with your soil... i.e., it's not too "hot" ... Best of luck - things are looking really good!

If you can add more perlite or other things like it, it should be fine. One way to reduce impacting of the soil is to water slowly with a sprayer. over the course of 5-10 min. Good Luck!

it doesn't look too "hot" in diary you may just have to wait a bit longer to fertilize.. maybe, wait for hint of deficiency before ramping up fertilization? gnats -- Bti.. Bacillus thurgen-something or oether (israelis subscpeicies). .. mosquito bits or dunk has this bacteria. It will kill most larva in soil. Great preventative measure... never worry about those little sacs of shit chewing on your roots... not just gnats. Sometimes this stuff simply comes in the packaging.. lying dormant until we use it. waiting for top 1-2" to dry is a good habit to form, especially if your soil is a little "heavy." Even in soil you want some runoff to ensure you saturated entirety. excess runoff is not important like in soilless context, though. (if you run into problems and change a formula.. 10-15% runoff is a good idea to force a new equilibrium in substrate faster) in future just add some perlite to balance soil 50/50 with drainage parts (some may come in packaging already, but more is often needed)... soil is always a balancing game.. how long before you add nutes? then, ramp it up to a normal dose once the soil is sapped and you are providing nearly all it needs by the end. (living soil being someting a bit different) don't worry if a product is "for" marijuana... this stuff has existed long before this esoteric submarket reared its ugly head. plants generally want teh same things in same proportions but in slightly different concentrations. some exceptions, of course, but not as many as most would lead you to believe in their marketing. 99/100 you will find the same exact product without a marijuana focus branding and it'll be 1/10th the cost, lol... especialyl nutrients.. holy shit.. these monkey-businesses are selling ubiquitous chemicals for extravagent prices.. it's f'n hilarious.