MR: I know that I ask strange things, and bother with subjects others would simply ignore, but I am so glad you guys followed me through anyways.
TBTB: You do ask unusual questions which however keeps things interesting. It is a pleasure to deal with you too as you are considerate, respectful, responsive, smart, and a good writer-communicator. I also liked your reply about the golden/platinum RTCs.
MR: Is there anything other than the Nitrogen Cycle, filter effectiveness, and tank heating systems that I should be studying for a massive pond?
TBTB: In essence, there is no difference between a small tank and a large pond. All the principles are exactly the same. Things just scale up. Nitrogen cycle is very important to understand and one would be prudent to start testing their tank water from the get-go (BEFORE putting any fish in their tank). Tank needs to cycle, best is fishless cycling - one can either use fish food (e.g., pellets) which will rot and simulate fish waste or add ammonia. Cycling can be sped up 2 times, from 6 weeks to 3 weeks when seeded with the beneficial bacteria. Bacteria must be well fed, as mentioned either with fish food or with ammonia.
I'd recommend getting an API liquid Master test kit ($24 from Petsoltuions.com) testing for NH3, NO2, NO3, and pH. Temperature is a must of course.
When you know and understand the ammonia, nitrite and nitrate levels in your tank and what affects them (food increases them, beneficial bacteria colonies and water changes decrease them), you can introduce your first fish in there, understanding that the fish needs to be acclimated (adding your tank water to the fish's container little by little until it is mostly your tank water).
If you want to read about pond construction, I have a compilation of links you can find here in one of my threads:
http://www.planetcatfish.com/forum/viewtopic.php?f=4&t=33968&hilit=+blues
Another knee-jerk reaction: it may be better for you to consider living in tropical or sub-tropical climate on a well water when you are ready for your dream. Heating 9000 gal can break almost any bank, unless you are made of money. Otherwise, very serious attention will have to be paid to insulation. It can be done. Ted from Seattle (see my compilation) has a tropical 1800, 4000, and 8000 gal pond OUTSIDE but I am sure it is a great pain in the neck to keep it warm enough still.
MR: What about the Ph of tanks, I know this is freshwater, and I am assuming that Ph should not be too big a problem.....but I might be wrong in assuming so.
TBTB: I am of the mindset (there are those opposing!) that the vast majority of fish sold in the US are adaptable enough to be adequately housed at any pH within 6 to 8.