could be that you're overwatering them. Apparently the symptoms of overwatering and underwatering look the same. Try watering less and see what happens.

Thanks Louisa I will let them dry out for a bit and see if that helps I'm new to GOY but I'm enjoying it seeing that I'm not alone with my mistakes.

we all make mistakes Kaiglen, no matter how long we've been gardening, there's always something new to learn:)

You water them when they are dry. You mustn't over water them.

Thanks Linda will try that as I really like Streptocarpus and would hate to lose them.