Help me make sense of my water paramiters

[Apples&Endlers]

I have been keeping endlers & pomacea bridgesii snails now since 07' I have had no issues really and never kept up with the numbers but in the last few months I have had some snail deaths that are unexplained so I am trying to figure out what I need to do to make things more hospitable.

I have a "few" :lol2: tanks and all pretty much have different readings so I am going to list them and hope that someone can help me out. I use API drip tests all are new.

#1 10g
Ph = 6.0
Kh = 89.5
Gh = 89.5
NitrAte = 20

#2 10g
Ph = 6.0
Kh = 17.9
Gh = 71.6
NitrAte = 20

#3 10g
Ph = 6.0
Kh = 17.9
Gh = 53.7
NitrAte = 10

#4 10g
Ph = 6.4
Kh = 17.9
Gh = 35.8
NitrAte = 10

#5 20g
Ph = 7.6
Kh = test only went up to 12 drops = 214.8 & I added 18
Gh = 35.8
NitrAte = 20

#6 25g (this tank is a month cycled after a total clean)
Ph = 6.0
Kh = 107.4
Gh = 35.8
NitrAte = between 5-10

#7 20g
Ph = a bit higher than 6.0
Kh = 17.9
Gh = 35.8
NitrAte = 20

If anyone has any suggestions they will be welcome. Keep in mind even though I have had these tanks for this long I never learned what all the stuff meant and how to adjust it to be stable. Never needed to since I never had any issues at all.

 

[jm1212]

what are you feeding the snails.

also keep in mind that sometimes snails just die without any reason. its kinda part of the whole circle of life thing.