If you are using nutrients properly than most likely your issue is environment or irrigation. Be sure to check the VPD and ensure you’re running your humidity and temperature properly. If you don’t already have a hygrometer I suggest you get one, here is the one I use:
Regarding irrigation, it is as important not to over water as it is not to under water. You don’t want to stress your plants out with a drought but you need to let them dry down so as to force the roots to build-out and grow in search of water. Super wet root zones don’t develop and therefore the plants don’t yield.
The optimal situation is to setup a drip irrigation system using Netafim so you can feed a little bit every hour during daylight hours only. From about an hour after lights come on to about an hour before they turn off. This is more inline with how you feed a human or animal, they cry for food and you know they are hungry, not force them to eat a huge feast and then wait until the next day. I’ve seen more farmers stunt their plants by over saturating than anything else.
Try this grow media for great aeration/moisture ratios: https://www.rfagriculture.com/riococo-blocks-super-washed.html
It comes in a 4.5 kg dehydrated brick for under $10 and therefore is cheap to ship and supplies about 4 bags of hydrated coco. Also, it is OMRI certified. Fill a pot and you’ll find this coco looks and feels more like chunky, airy soil than the coco coir you may be used to seeing at hydro stores. Plants love it and it cut down my veg and flower times by about a week.
They also sell a 4 x 4 x 2 product if you want to move your plugs into something smaller with more control that you can later drop into a pot or set on top of a block. Here is the link for that: https://www.rfagriculture.com/riococo-starter-blocks-super-washed-10-cm-x-10-cm-275-case-54-cs-pallet.html
Only problem there is that they come in a pretty large case size. I asked them for a sample and they sent me some for free.
If you ultimately decide to continue hand watering be sure that before every feeding you lift the pot to check its weight and also start to dig down a little to ensure the soil below the surface has also dried down. Sometimes the top looks dry but the root zone is still sitting in water. Hope this helped.