Not enough if yu ask me. I guess its all comparable to what the plant needs. but I give 3l about every 3 days at most sometimes every 2 days. water slow til slow run off everytime to make sure its enough.dont let it get so dry before watering again. def hurts the yield. try doubling once a week and go 2 times. if she reacts poorly after the first time than don't,, but one overwater will not hurt too bad to make sure yu are giving her adequate nutrients and water. but 3 l once a week cant be enough if yu ask me. In my 7 Gal I use close to 3.5L every 3 days, in my 10 Gal more like 5L every 3 days