My sad Elkhorns

I have three of these- but they are looking sad, crispy and droopy. Here’s what I’m doing- please give advice on what might be wrong!:

• they’re under full shade on my patio- ambient light comes in
• I was watering them daily- but switched to weekly when I heard you can overwater them. They have been getting weekly waters for a few weeks and looked sad either way
• they have been fertilised once with indoor plant fertiliser