Help for off grid design

I am looking at 6 100 watt mono panes with a morningstar TS- 60 diversion load control. I want to wire the panels with 3 groups of 2 panels wired in series and the the 3 groups in parallel for 24v at 300 watts to start.
If I add a 24 volt water heater diversion element that draws 900 watts will it try to pull from the batteries or will it just take the full available panel power just working at a lower efficiency.?
eventually plan to add enough batteries to run my well pump off grid with an inverter (10A at 240 VAC), but for now I will just be running the Iron filter and softer + some 12VDC yard lights.
Am I heading in the right direction?  

I just bought panels and parts for my off grid system, and was curious if you found the 100 watt panels better for a particular reason, than say buying 2 300 watt panels to put in series so you get the same voltage/amps? You'll still get 600 watts with either combo not 300 watts. 300 watt panels tend to be far cheaper compared to 100 watt panels, per watt, in my experience.

Lighter and easier for me to work with. I usually work alone and will be putting them on a south facing carport roof.
the 100 watt panels are 109 with free shipping

the 300 watt are 277 + shipping  there won't be much difference after I pay the shipping, but I need to order panels today to get the price & free shipping. I have been doing some research and I think I have the correct setup but I was hoping to hear from some who knows a lot more than I do about the diversion load.

Ah gotcha, I ordered mine from altestore.com for $172 per 300w panel. Definitely heavier per panel, and safety is a biggie!

Are the panels plugging into a charge controller which has the diversion load attached? Is the goal to heat water when batteries are topped off, rather than the typical charge controller just cutting the current?

Yes, instead of letting the excess power go to waste the goal is to provide some "free" heat to the hot water heater by replacing the lower element with the 24VDC element.