Even with the hard water I would use your tap water and a dechlorinator Prime as suggested.....more due to cost since you need to do more water changes and as posted the bottled water can often lack the needed minerals the fish needs for good long term health....Bettas adapt really well to pH and hardness of water....I would start to wean them off the Betta bottled water by making some 50% water changes with your tap water and dechlorinator...
Long term sodium chloride is not needed or good for them.....especially in the wrong dose, duration and reason.....you can create resistant pathogen/parasites and cause kidney failure...it great for short term treatments when used in correct dosage, duration and reason......
I use the bottled water you can get at the pet store.. I use the Jungle 6-in-one test strips, and the water rated 300 (max) for water hardness when run through the water filter (it tastes gross.. I use bottled water myself, the tap water tastes like a swimming pool).
And I only add aquarium salt after a 100% water change. I usually use half of the 'suggested' dose (i.e. 1/2 tsp per gallon as opposed to 1 tsp per gallon.. I don't have the container with me atm).
I just did a 100% water change.. Zen and Om (his shrimp companion) are casting baleful glares in my direction. They're still in their holding bowl while their tank returns to the proper temperature and they're not appreciating it LOL
I would stop using that. That's expensive and unnecessary, to be honest. Tap water that is conditioned works better and has more nutrients. Is it the blue water? Thats a load of crappolah, if you ask me! Hmph!
Prime as said is great, and so if Top Fin's conditioner, which needs only 2 drops a gallon as well.
Test strips are inaccurate and will skew your readings. Instead, opt for a liquid testing kit. Adding the dechlorinator will make the water safe. If youre really nervous, add in an extra drop or two to make sure. Mine smells like that, too.
Are you treating with AQ salt? It doesnt do a whole lot when not at the right dose, IMO...Its like taking half an aspirin. It doesnt work well. 1tsp/gallon works wonders for ill fish, but try to (for the future) not use it for more than 10 days, as it can cause damage.
If youre gonna use the salt, use the whole dose.
Also, take care to properly acclimate the fish and shrimp (especially the shrimp..) in their weakened states.
By using low dose salt you can create resistant pathogens/parasites and when you need the salt for a treatment it may not be effective, you also can risk kidney failure with long term use, however, with this species due to their short life span to start unless they are compromised already you may not see this problem with low dose until they are in the 2yr range....usually the first sign will be edema for unknown reason in a healthy looking fish...
When I step out of the shower, I feel like a piece of parchment paper. I can't imagine what the fish feel like soaking in it. But I'll try your suggestion. I just didn't want to subject sick fish to such harsh conditions.. but now that King Louie and Zen are perking up a bit (or calming down, in Zen's case.. he's draped over his leaf hammock, surveying his realm once again), I will try introducing conditioned tap water in a partial change next.
Om's munching on a betta pellet.. he's still so tiny, it looks like he's sucking on a basketball
They usually dont/cant do anything, save a really powerful dose of anti-parastic/ antibiotic shots.
I wouldnt waste your time in going. Rather, if you can, treat yourself or find a Professional Aquarist who cleans tanks/set up tanks/specializes in disease. Theyre not super common, but usually one can be found in a larger city.