Water issue

If you are seeing the white granular material in the toilet line, I hope it is not related to the water heater!

Do you have some vinegar? If so, drop some of the material in a small amount of vinegar. If it dissolves and fizzes, it is hardness scale (calcium carbonate). You would need a water softener to prevent this material from forming.

The corrosion product from an aluminum anode rod is aluminum oxide. It also will dissolve in vinegar, but slowly and without fizzing. The best way to prevent problems with this material is periodic maintenance of the water heater.

If the material does not dissolve in vinegar, it likely is sediment from the water source. A "whole-house" sediment cartridge filter would help.

We flush our complete water system (2) times yearly with a "generic" white vinegar/water mixture(1gal of vinegar per 15 gal of water capacity of your rv) and additionally flush the water heater with a hose wand attachment after running the mixture through "all" the lines/fixtures, then letting it set for 4-6 hrs.(http://www.campingworld.com/shopping/item/water-heater-tank-rinser/49070) You should also have a screen washer at the fresh water hose connection which will help trap some sediment. We also use the filters shown in this link as they do a good job of blocking incoming sediment with minimal reduction in flow rate.

http://www.amazon.com/gp/product/B00BEDNXTW/ref=oh_details_o07_s00_i00?ie=UTF8&psc=1

What is it: Normal mineral deposits that happen in nearly all plumbing systems.

Is it contributing to your water heater issues; Depends on the issues. if the issue is an outlet check valve stuck closed. then YES.

Thanks for all the replies!

We have an Atwood WH so no anode rod.

Yes it is some white granular stuff clogging the aerators. looks like its clogged the water lines in the toilet. I guess I need to get a filter. I've never wanted to use one because of the drop in water pressure. But this is a big problem to get rid of.

Granular suggest sediment got into the system or possibly the anode rod. Atwood does not have one.
Is the stuff clogging arerators white in color? If so it is lime, magnesium etc.
Even with filters lime in solution will get though. Lime in suspension will be caught in many filters and it will gather some, of the lime in solution, out, of the water.
You didn't say if you always use a water filter.
A water softener will take lime etc out but you still need a filter before it.
Lime and sediment will cause plenty of water heater problems.
First water heater, in our old home, had perhaps two hundred pounds of lime in the bottom when we changed it out. Had to replace several heating elements that lime coated and caused failure. It is well water. A filter solved the sediment and some, of the lime problem. Water tasted excellent though and several Folks came to just get our water.

What kind of water heater do you have? Some use anode rods, some do not. Available at most any camping supply store.

We typically use a city water connection at campgrounds. Every now and then we stay in a National Park or Corp of Engineers campground were we have to fill the holding tank with water. This has always been a problem with this coach. We've had it for almost 3 years.

Were can I get to this anode rod?

Breakdown of your anode rod (normal), sediment in your water i:e: calcium, salts.
Do you use city water, well water ?