QUOTE
Every other day farmer
1 litre each
Definitely your watering regime that's causing this mate. You shouldn't have to water them that often really.
Don't give them a litre, keep giving them water until you see run off through the bottom... make sure they're properly saturated. If you have suitable trays, let them sit in a bit of it too (not too much, or you'll wreck your roots).
Then don't water them again until the soil almost completely dries out (not completely, otherwise they'll wilt... you want to catch it just before they do that, and also before the medium starts to crack up/break away from the edges of the pots).
Usually works out at every 3-5 days.