My leaves are yellow, I'm not sure if its due to light burn, over/underwatering, or any of the hundreds of other things that could be wrong.

Them plants need some nitrogen.. get some liquid feed and give them some and they will be back healthy and happy mate

Growing is easy, though. Overcomplicating it is often the problem. it's not mystical.. it's just rate of inputs vs rate of growth. A proper balance (ratios) and concentration is equally important. They look a bit hungry, but it's hard to tell under some grow lights. If they are pale in normal lighting, then definitely look slightly hungry. looks like the one on right needs a little more K -- the tip.margin burn. On lefty you got interveinal chlorisis which can be a few things. Can't tell for certain... no coinciding spots, so Mg is less likelyi and it doesn't look like they are from an overdose unless nute ratios are far off. This is part of why i think they are not irrigated properly.. it looks liek a trace element issue, which is incredibly rare problem in most contexts - soil or hydro nutes pretty much include them within needs... is this soilless? adjust concentration to 1.3-1.5 EC and fertigate every irrigation with 10% runoff - err on high side rather than low side. if you can do a weighted average relative to amount used per gal or liter etc of the NPK values from all products used, 1-1-2 (or more resolved 8-8-15) is a good raito balance to start in soilless - Ca, mg and s vary due to tap water used, but it should all add up to 1.3-1.5EC. Allow top layer to dry before repeating for lowest risk cycle. Pot weight is a great way to judge water volume needs. If you want to try more frequent fertigation, make sure some minimum amount of weight loss has occured in the pot. 25-33% can really push it... but even 50% will be sooner than top layer drying and be fairly safe... i'd form a baseline doing it the proper way first, then try this after you get everything else on point. soil? fertigate ever 2nd or third irrigaiton. wait for top 1" to dry before repeating. how you "add k" for the one plant depends on products used... assuming no other issues, try increasing does of component with higheeat K value on label... or the product that can impact it while doing less to others is the general idea here. I'd guess you need more N, too, but the way the pots look i suspect irrigation habits are part of this and fixing those first, then re-assessing is a good option... if they take a nosedive in the meantime, increase N concentration of fertilizer. Soil is more trial and error and depends significantly on what came in the soil to start. pretty hard to give any exact suggestions without experience with exact same soil used. Get your ratios and concentrations straight and it'll be easy-peasy. only minor adjustments ever needed... Leaves get a little too dark? you drop N, etc... N will be the thing you have to adjust most per unique plant... greater control over environment will reduce need for adjustments too.

I sparked a joint before i began writing, i had a bunch of more useful shit to say but i forgot what exactly it was, good luck!

Want to ensure complete dryness in the medium between each watering if you can, a tiny bit of drought stress is actually preferred, the plant is hardwired to droop in response to conserving water, and the plant still has supplies of water of around 24 hours at that point, meaning so long as you visit at least once a day all you need to do, to master watering is wait until the plant clearly visibly droops, so long as you are diligent and catch it within 24hours it becomes a good way to measure until experience allows prediction.

Hey brother, no one ever said growing was easy !, You're doing good man relax, it's a weed after all. Sellers often sell led lights and will use the "comparable" wattage, which is how much PAR (Photosynthetic active radiation) is created in comparison to the much less efficient "old-school" style of growing that used HID High-intensity discharge or Fluorescent tubes. Your light is more likely 100-200 real watts. You using plastic pots, there is nothing wrong with that, but it can be tricky to water correctly and this can lead to eager growers overwatering very easily. The problem is not with the water per se, but more the lack of air that is able to take it away, stagnation is your enemy, when water is allowed to sit for any length of time, it will provide a prime breeding ground for bacteria, growth rises exponentially above 77 also to keep note, so unless environmental conditions are in check you are just asking for trouble. This especially holds true for the flowering stage when perspiration really cranks up. First off you need to know your PH otherwise it makes diagnosis useless, even if we fix deficiency the PH imbalance would prevent nutrient uptake, in this case, its possible a few things are going on, 1 thing led to another, the plumbing is clogged either by overwatering or a nitrogen deficiency. Nitrogen uptakes best at 7.5ph and reduces drastically around 5.5-5.8. once you verify ph to around 6.5-7, this should start the flow of nitrogen again, if it's not the ph then it's the early stages of good old bacteria OR nitrogen deficiency, you want to rule out bacterial though before you feed more nitrogen.. not sure if your pots are plastic or ceramic if its plastic try drilling lots of holes all over and make it air pot, highly recommended fabric pots or airppots , they are far more forgiving and make watering much more carefree. Good luck brother stoner! May we TOKE ON!

Need more information, hard to diagnose these things with little to no info, could be a ph thing a nutrient thing a watering thing, I am with Ezzjaybruh, zero signs of light stress. You should start a diary it's fun free and great for others looking to grow the same genetics.

Cuz if you’re legit 6” from a 1200W light you’re frying the fuck outta it. But that’s not the symptoms I’m seeing

Before anyone goes down the light burn avenue please post the exact light. Many claim “1000W+” but are usually 100-250..