Let me address some of your questions.
up to 75 degrees is good. Yes, shrimp can live in 78 and beyond (and I've kept mine in water up to 84 before). The higher temperature you keep your shrimp at, the faster the life cycle, and you run the risk of bacterial infections and faster death.
Think of this equation:
L + T = K
L= Shrimp Life
T= Temperature
K= constant
In order for K to remain the same, L and T are on a tettor totter. If one goes up, the other goes down and visa versa.
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Copper in most foods (and shrimp foods) and fine. Shrimp uses copper in their blood to carry O2, so they must have it for their bodies to work correctly. It is when medications are used- usually for fish- that contain copper that it becomes dangerous or lethal. The ingredient for getting rid of snails in an aquarium for instance is copper. Since it kills snails- which are inverts- it will kill your pet inverts (shrimp) too.
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Shrimp from a bad environment are often not healthy. The thing is- it takes them time to die. So what may look as hardy shrimp in a bad environment, often is unhealthy shrimp slowly passing away.
Ghost shrimp from the pet store often don't live very long since most are collected wild and care is neglected since they are to be used as feeders.
As shrimpers, shrimp are a little more sensitive than fish. So we take special care to look at TDS, Gh, Ph, Kh, as well as regular fish params. Unfortunately some of these tests are not included in a regular freshwater master kit, and strips go bad quickly giving inaccurate information- so liquid tests are preferred.
Some shrimpers use tap with water conditioner, however sometimes things sneak into the tap that fish can handle but are problematic for shrimp. To get around this many shrimpers use RO (even bottled from the local food store) and remineralize with this. There's a smaller size too and also other remineralizers out there. Oblongshrimp on here sells Salty Shrimp gh/kh which may be more beneficial for neos, however I've not tried it yet.
Some general params for cherry shrimp:
PH: 7+
KH: 0 – 10
GH: 6+
TDS: 100-200+
Water temp: 70-75F
There's people who have successful colonies different from those params, but listed is kind of the avg. people do.
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Acclimation is different from acclimating fish. Here's a good link to see how it is done:
http://www.shrimpnow.com/content.php/258-Acclimatising-Shrimp
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I see you said planted tanks. Do you use ferts or CO2? Shrimp, in general, do not do well with CO2 or ferts in the water. There are some who have managed it, but most of us do very low tech for the shrimp to do well.
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Cherry shrimp come in many different varieties of colors and are one of the hardiest to learn with since they can take "Oops" a whole lot better than the more sensitive shrimps. (Yellows and Blue Diamonds are very sensitive as far as neos go. I lost hundreds of dollars on yellows, and had to develop my own strain- but that's a post for a different day. heh)
Hopefully this answers some questions?