However my problem is that I have very hard water. TDS approx 200 out of the tap, pH about 7.5-8. No copper thankfully...GH and DKH were both high I don't exactly remember the values, I think it was 10 and 14 respectively.
That's not hard at all! I've heard of people keeping Neos in water that's 20+ dGH! I tested the TDS of a "pond" that some shrimp and fish lived in, and the TDS was over 600! I use RO water usually out of a Primo machine, but have also used Glacier.... runs 33-50 cents a gallon. This usually has 0 GH, 0 KH and very low TDS (<5). I then add minerals to it using shrimp minerals.
I'm one of those people who can't keep Neos in tap water.... because it's too soft. I also don't recommend it, either, as you then don't really get to know how to keep shrimp. So many people hear that you can keep Neos in tap water just fine without any mention on their preferred or ideal parameters, get shrimp and the shrimp die... they have no clue what the ammonia, nitrites, nitrates GH or KH is out of tap and that can make a huge difference!
Some people are lucky and never have any issues.
And then there are others who get those parameter swings that was mentioned. I recall reading one person who lives on a farm and had no problem using their well water.... that is, until a neighbor up the way used fertilizer or something on their farm, which contaminated the water. The person who had the tanks wasn't aware and did a water change as normal on their tank. Everything in the tank died... or others who live in a city that may occasionally use heavy doses of some sort of sterilizer or cleaner that, although is "okay" to drink, is not invert safe.... and kills off a tank.
An alternative to RO water or distilled is rainwater... if you live somewhere where it's legal to collect rainwater and you are away from contamination in the air. If you used rainwater only, you would need to add minerals back into it.
I am wondering if it is worthwhile to use mineral supplements (i.e. Fluval shrimp mineral supplement for example), or if my water is already way too hard. I top up the water with distilled water but my water changes are mostly tap water because I can't afford to use distilled water for 100% of the changes. Also if anyone has any advice on other things I should add (alder cones, etc) please let me know. I am making a trip to the not so local LFS tomorrow and they specialize in shrimp.
Only if you use RO water, distilled or rainwater would you require a mineral supplement. Salty Shrimp is pretty popular, but there's several brands out there! Alder cones, indian almond leaves, birch leaves, guava leaves, mulberry leaves, bamboo leaves, etc... lots of options can be used for in tank!
Also side note: Anybody have any advice for medication if things go south? I've heard paraguard sometimes works but may not be invert safe?
I'd have to say that medications should be based on what's going on.... i.e. scutariella or vorticella, salt baths or Paraguard can be used to get rid of the 'leaches'. Bacterial infection, lots of options there and I don't know if any are ideal. Ellobiopsidae/green fungus/algae (what it actually is), again, many options, no guarantee any would work...