Test you tap water directly from the tap. Take a sample in a clean cup rinsed well in the tap water. Test it again from that same cup 24 hours later. Check the level aginst the first sample and the tanks. For now, just add 1/2 tsp. of baking soda to the aquariums water. Check pH in 2 hours. If needed add another 1/2 tsp of Baking soda and check in 2 hours, repeat 1/2 tsp. every 2 hours until level gets to 6.8pH. Check again in 24 hours after 6.8 is reached. Sounds like you have all in one test strips, they are unreliable get a reagent type like API master test kit. Also, I guess Al is ammonia? if so when ammonia is high it can lower pH. Looks like your ammonia levels is high, get ready to change some more water if it gets to 1.0. If your water is natrally acidic, look to it as a blessing. Raising pH is easy, lowering it is a PITA and expensive. If your water is acidic add a couple of seashells to the tank or get some crushed coral that is sold in the salt water fish sand and gravel aisle of your local pet store. Just a small bag. Take a scoop and put it in a media bag or old clean stocing and put it in your filter. Seashells and coral are pure calcium carbonate and will buffer your water long term. You can use the baking soda just for a quick dose when changing water out durring maintainance.

I just happened to come by this forum for maybe the second time in several months. This gets into several issues that are about technology. There are several very sharp people who address these sorts of issues daily, but on other forums in this group. See "irrigation" which is under "professional topics", and especially "plumbing" and "electrical wiring" under "That Home Site" (linked). I suggest you repost this on the electrical wiring forum. I promise you will get useful responses quickly. It will be better to get others involved from the beginning. Now, a bit on your questions. Number twelve would not handle a second pump at 500 ft, you are limited to one 1/2 HP as it stands. Voltage drop is already an issue at the 3% voltage drop standard, probably okay at the 5% overall drop standard. This is based on a nominal 4.9 amp draw for the 1/2 HP. Alternating pumps would be technically possible but probably not the best solution. Could the storage tank be located near the house? It would be simpler and probably better to have independent power to the second pump. Output from a good 1/2 HP sub in a tank at the lower elevation would be about 9 gpm at 50 ft. + 50 psi. That might be a little small. I also wonder if the storage tank could be smaller. What sort of flow and volume demands would you like to serve? What is the time frame? Answers to those questions will influence the choices for the second system. Here is a link that might be useful: see plumbing & electrical forums

A softener would absolutely take care of 1-1.5 ppm iron, provided a high salt dosage is used for regeneration, regens are done every four days or fewer and steps are taken to strip the iron from the resin. If you choose to regen with a low salt dosage, you would need ar larger softener, not a small one. Any "standard" resin will do - not DOW. Again, I just want to make it clear that this is a recommendation specific to your situation and water treatment goals and is not something I would normally recommend. If you do a hard water bypass you would do it AFTER the Fe/S removal and BEFORE the softener. If you don't install a separate Fe/S removal and you do a hard water bypass, you will continue to smell sulfur compounds and have iron staining.

I'm having a new problem with my well water: when I'm running water the pressure will get to about 20psi, hold for about 5 seconds, then drop to 0! After about 2 seconds at 0 I can hear it kick on, and then the pressure jumps up to 20 and climbs back up to 50. I replaced my pressure switch and well pump in early August of this year (close to 4 months ago). I replaced the pressure switch myself with a Square-D 30-50psi with an Auto/Start/Off lever. The model is FSG2J21M4CP: https://www.amazon.com/Square-FSG2J21M4CP-Standard-Pressure-Switch/dp/B0002YSOPM That didn't fix the problem, so I hired a plumber to replace the well pump. He said that it looked like lightning had ran in on it. It also has a Wel Flo Pre-Pressurized Water System Tank, model # 24221808, that appears to be OK. What do you all think... faulty pressure switch?