Darknight

Awesome. I'll hopefully be able to get another panel within the next week or so. My current panels are canadian solar 330w. I'm going to try and get the fourth panel from the same supplier but if they're out of stock, I'll have to go with another supplier who has canadian solar panels, but his are 385w if I'm not mistaken. I'll post an update once I've got the panel installed etc.
Thanks everybody for the help.

Sorry, didn't see this part. From what I've seen from the readings on the inverter screen, my input pv voltage from the panels during the day is is usually between 31v and 35v. 
When the mppt draws current from the panels, does that reduce voltage? 
By wiring the panels in series, that would increase my voltage but leave my amperage the same. Each panel has a Vmp of 29.4v (NOCT) and an imp of 8.34a (NOCT). If I wire the panels in series won't I be restricting how many panels I can run because the max pv input on the inverter is 102vdc and by wiring my 3 panels in series my voltage would already be 88.2v?
Do you think adding another panel, while keeping the panels wired in parallel (or series-parallel) would prevent the mppt from switching off after drawing current?
Or should I just try to add more load to the inverter during the day?