More than a half gallon every other day is a lot of water. You have to watch out when you water that much the bottom of that pot could be saturated and it might appear to need water but it does not. That's a gallon of water every 4 days,it is just way to much water. Mine are 5 gal buckets and in the beginning of flower when they begin to really work hard and they use a liter a day until about week 6 or 7 when they really go into heavy flower then they can take up to 2 liters a day. No matter how much water you give them will never fix a problem you just have to make sure the new growth is not still coming up with the same problem,sounds like you will be ok. I give mine cal mag and silica as soon as they establish a root system. If you over water bad things happen like cal mag problems caused by lock out. Do your plants droop or give out towards the end of their light cycle? They will droop for two reason under watering and over watering. Also remember that if you can use cal mag as a spray,once you have cl mag or any disease the plant has it although it may not show at first then like any other disease it erupts and you can only ride it out. You should be ok as long as it is under control and is not spreading to the top end of the plant. They will make it just make sure that the plants in no way get under or over watered,you have to make sure that you are spot on with the watering and feedings. You should be able to make it all the way to the end you just have to be on top of it. It sure looks like cal mag problems . How is your ph reading going in and coming out? I hope i helped a little bit. most plant problems are brought on by us as growers. Good luck you will be fine just look at this as information whether or not it is not the problem. Ph,over and under watering,plant environment and over dosing with nutes are the main things that we new growers have a bit of a learning curve or we wouldn't be here.