I think the main problem is they got off to a slow start and they're being a little overwatered. If you're seeing discolored leaves the pH could also definitely be a culprit. Now that the flowering stage has started, they're not making new vegetative growth as much, and the plant is struggling while it's also trying to make buds at the same time.
I think you can save the plants, and the quality of the buds will be good, but since they are autos that have already started flowering, they're not going to get much bigger at this point. That means you're going to get really small yields with these plants. If you want my honest opinion I think you should put them in the corner of the tent and start some new plants at the same time if you possibly can. You're spending money on electricity to run those lights, and you want to make sure there's enough buds in the tent to get your time and money's worth!
Starting in smaller pots definitely helps prevent overwatering. Some people
start in solo cups for that reason and transplant their seedlings to bigger pots around the time the leaves reach the edges of the cup. As long as you don't stress them during the transplant process this can help them get a really fast start. Another thing you can do if you do start seeds in big pots is water them in a small circle with just a cup or two of water at at time at first. Their young roots can't drink much. As they get bigger you should start watering enough to get runoff out the bottom, so the roots find their way down, then wait until the top inch is dry before watering again.
I'm sorry it's been frustrating, I think we've all been there! But I think you can salvage the buds from these plants, and if possible get something else going at the same time!