MTS & Thier failure to thrive

["Allen Smith" <plecosaur at hotmail_com>]

Hi.

I have had a problem over the past year or so in trying to introduce MTS to
two of my tanks.
I have 3 tanks all together.

The 3rd tank is the source of my MTS, it is a 20 high tank with 1 angelfish,
and 2 assorted tetra's a rummynose I believe and a flame tetra (leftover
from rescuing someone's tank). The gravel is neutral, does not effect the
pH, the snails thrive in that tank, I routinely pull out 30-50 full size MTS
snails each month (I don't even bother giving them special food etc., I feed
that tank very little) and try in vain to introduce them into my other
tanks. In addition I  had 2 small ramshorn snails in the 20 gallion, but
they died after about 1-2 months, their shelled became whiter, and looked as
though they had gotten pitted in some areas.

One of my other tanks in question is a 55g with a 6" oscar and a large 8"
sailfin pleco, the gravel is neutral and pH is around 7.0 I believe - I
haven't tested that tanks pH & other parameters in quite a while. However,
our tap water is pH 7.0, gH 3, and kH 5 if that will help - that is a recent
measurement (as of this month). The reading is is relatively stable even
though we are on well water. Sometimes the pH will drop down to a 5.8 (or
lower) during certain times of the year, but the gH an kH remain the same -
the fish seem unaffected by the change in pH, no loss ever due to the
difference in pH - no matter how severe.
The other tank is question is a 72g high-tech heavliy planted tank with CO2
injection and 220w CFL (I believe - can't recall exactly) lighting. The
inhabitants are approximately (the things keep breeding - so numbers are a
guess) 6 black kuhli loaches, 4 normal kuhli loaches, ~ 30-40 cherry barbs
(they are very prolific in their breeding, a new batch each month
unfornately), 1 female pearl gourami, 1 clown plecosomus, ~ 6 otto cats, ~ 4
SAEs, 2 or 3 assorted zebra & leopard danios, and 3 white cloud minnows.

This is my problem. In either of these last 2 tanks the MTS end up dying
after 1-2 weeks. Their shells appear to get whiter (if that gives you any
clues) or they just plain disappear somewhere.

When I introduce them to the other tanks, I pull out 30-50 mid-size to
full-size MTS from the 20 gallon and drop them into whatever tank I'm
feeling an affinity for at the moment. Is this the wrong approach? Should
they be acclimated, say like fish, take some of their water, put them in a
bucket, and slowly add some of the tank water there, until I feel they are
ready for a new tank? I was considering that - but it seems like no one does
that for snails.

I have the following theories that I have concocted: 1) in the 72g the kuhli
loaches eat them - the babies at least, I find this unlikely as MTS are
tough-shelled and I don't think the kuhli's could kill them (all the shells
are still intact, even when they are dead). 2) I have a calium deficiency
with my low hardness, but if this is true why does it not effect the 20
gallon? I do not know how to test for this, is there a test kit I should
aquire? 3) In the 55g with the oscar and pleco, I see no reason for them to
perish, there is plenty of excess food and nothing that would see them as a
source of food - even the oscar spits them out if he feels so inclined to
try to eat one. 4) Following the previous theory, they have no food in the
72g. I find this highly unlikely as I feed quite liberally and I believe
there is more than enough extra food for them to live on.

Any help or ideas would be much appreciated. I've been struggling with this
for well over a year. I would much like to see MTS in my other tanks as I
enjoy them and they are also benificial in many ways.

With baited hope,
Allen Smith