Sounds good, but 60 to 70% water change? Seems super high, but........ with a lot of things and each person and their aquarium. If it works, don't change it. I need to add a photo sometime here. I do have a lot of plants, but I also have soil under my black sand. So as far as minerals, I have a lot. Plus I have oyster shell in the bottom of my HOB and under the substrate. I use a pinch of Epsom Salt, (100% Magnesium sulfate) every so often. It's good for ailing fish and adding minerals. I think your right, all fish born in the same tank will do better. They didn't have to adjust to a new environment or water perimeters. Have you tried Snowflake food? I read it doesn't dirty fish tanks much. I haven't but plan to order some. I also have a good LED light. I always order different lights than what comes with the tanks. I have a small grow out tank, 20gal. I have for all my plant trimmings. It's the only one with a crummy light. But with C02 and good ferts, they grow fast. It also works well as a quarantine tank for new fish. I really need some pygmy Cory's for my Shrimp tank.
Yes, a lot of water change due to too much debris and detritus worms in my tank.
I have to siphon them out every week.
If your tap water parameter/chemistry, temperature are the same and stable every week, usually you won't have any problem even with 50-60% of water change.
I'm not sure whether the Epsom salt(Magnesium sulfate) is the same as the salt (minerals) for shrimps.
From what I know, Epsom salt is a laxative. It's used for fish that have constipation.
Anyway, when your shrimps starting to breed, the next generation of shrimps will be adapted to your tap water and they will become hardy.
I suspect that the shrimp breeders may use reverse osmosis water with shrimp minerals and their GH or mineral contents could be very much different from our tap water.
This cause the ring or death and molting problem(my theory).
If we can get more information from the shrimp breeders, then we will be able to solve this problem.
I haven't tried the Snowflake before.
There are too many shrimp food nowadays.
I'm using about 8 types of shrimp food plus another 4 types of fish food to feed my shrimps.
We are spoilt for choices.
I think our shrimps have very good lives as compared to those in the wild.