First time with Brugs

It's my 1st year with brugs, I have 9, so far. Most I received from a lady in Ottawa. Actually I was suppose to get 4 and my sister 4, but she decided she didn't want them, because of lack of room. I received one in a trade. So I have 2 of the same.
I had read someone post, on the different disease or problem you can encounter with brugs. For the life of me, I've been trying to find that post, and can't find it anymore.
Most of the brugs makes nice leaves, then they either curl up and drop or they yellow and drop. Can somebody help me out, or help me find that post. They were showing pictures and telling us how to deal with the different situation. I will post a few pic of the problem. Can draft affect, these plant? Because 3 of them are close to my patio door, and I use it often.
This one has the leaves, that curls.

These are the ones near my patio door, with the yellow leaves.

And then I have one that make beautiful green leaves, that for no apparent reason drops .

You could have spidermites. Use a good magnifying glass and look at the underside of the leaves. Spidermites are eight-legged pests that suck the life out of the leaves and weaken the plant. Remove most of the leaves and spray with Neem Oil. It's safe and smothers the mites. Regarding that last one. If the leaves are otherwise healthy, I wouldn't worry about it. They can do strange things in winter when inside.

You might want to get some grow-lights to help with the light. If you are trying to get them to grow they will need more light.