Leaves curled upward with brown patches

None of the new growth has it but its happening on both of my plants. They are 4-5 weeks into veg. I'm growing hydro with General hydroponics nutes only. It is not nute burn and at first I thought it may have been light burn, but I moved the light and more leaves are being affected. I'm thinking either phosphorus or calcium deficiency after reading but I can't be certain. I would post a pic but my camera cord has been missing. They look terrible. Is there any thing around the house that could be used for a plant calcium supplement.

EDIT: alright, I just added 2tsp in the 5 gallon and 1 in the 3 gallon of GH Bloom which had the most phosphorous. Which I guess makes sense since the plant is getting older or whatever. The ph is fine and everything, So I think this should fix the problem. This is my first time growing and I've already had mag deff, nute burn, light burn, and now phos deff. hopefully next time itll be a smooth ride to harvest.

With hydro, it's easy, just flush the medium and change the res. I would say that you have signs of overfeeding. What amounts of MBG are you using? (Micro, Bloom, Grow)

Ya see, thinking that you are seeing a deficiency when you actually have a pH problem, or overfed plant, will just make a toxic medium worse.

It's always best to flush and ask questions later.

HTH

You were right potroast. I'm only using 1/2-1/2-1/2 tsp per gallon but the last time I filled the reservoir I think I used 1-1-1 or more because they looked yellow. I have a 1 plant in soil that is dark green compared to the 2 hydro plants. So yeah nute burn sucks, I think I only have 4 large healthy leaves on each plant left.