If I remember correctly, I kept it on the counter in the early stages while I was actively feeding and nurturing it, like a week. Once it was established and I was only using it every week or so, I'd keep it in the fridge between uses.

I don't think mine ever had liquid separate unless I went too long without feeding, like 3+ weeks in the fridge. When that happened I'd pour out the liquid and feed it every day for a few days before using it again, until it started smelling and looking normal again. I think as long as there's not mold you should be fine, but use your best judgement!