Pictures of my new tank 3month old

I have a well and I've been using this water that comes straight from the ground. If that is my tap water, should I not use it? What is an ro/di anyway?

RO/DI is Reverse Osmosis De-Ionized water. I've been using the same until for over 5 years to purify the water coming out of the faucet in my home.

The one pictured on this page is my personal system: http://www.melevsreef.com/ro_di.html

Well water often contain metals, and possibly contaminations such as pesticides and fertilizers. If your tank looks good, you've been quite lucky so far. Some people living on a well have to use a water softener because of the high alkalinity right out of the ground.

I suppose that is one more thing I should buy. I have never even checked the Alkalinity nor do I know how. I also never check Ph. My tank is doing well. I just do not have the Coraline algae that I would like, but that is due to not enough LR in my tank. Isn't their a probe of some sort that checks all of that at one time?

No, but these are the things we normally check for in our water when keeping a reef tank:
http://www.melevsreef.com/parms.html

Regarding RO/DI systems: http://www.melevsreef.com/why_rodi.html

And for well water, I would think that there is some type of service offered to you and your neighbors that tests for arsenic, copper, other metals, phosphates, nitrates, chloramines, etc. It should be a complete write up. We get one but we have city water. I think it is required by law, but maybe not for those using wells.

A TDS meter just tells you how many total dissolved solids are in the water, but it won't tell you what they are.