thanks for some understanding on the tds/pwt meters.... but, once again the 
newbie needs some advice... i posted this on another cs board, but as of yet 
i've had no response, so i'd like to pose it here too:  about 2 months ago we 

purchased the cs300 to produce our own cs, but soon found out that 
making 8oz. at a time was too time consuming, esp. when we were using 
large quantities ourselves, and giving it away to family and friends 
by the gallon (great reports by the way)... anyway, within a month i 
knew our needs far exceeded this small unit's output unless i was to 
spend every minute brewing cs... so, a month ago we purchased a cspro 
to make a gallon at a time... this has been wonderful, and out of my 
first 5 gallons, i've given 3 of them away... today i went to brew 
another gallon for ourselves (the 6th) and i noticed that the rods 
were not looking the same as with the first 5 gals.... lots more of 
the dark stuff, none of the 'smokey' silver in the water, etc... i 
realize the 'tds' meter doesn't register the true ppm, but i do use 
it as a comparison guage, and was getting a reading of 000 to 001 
after 15 mins.... now 15 mins. would normally bring me a brew of 10 
or better... anyway, here's my question(s): how many gallons should 
i be getting from .999 silver 12 guage wire? is the wire solid 
silver or overlay, and when the coating is gone, does the black flaky 
stuff appear? in cases such as this do i brew it longer, or do i 
just replace the silver rods? i was thinking i could supply everyone 
with tons of cs, with such a minimal cost (and i guess it still is, 
considering a gal. goes for about $75.-$100.)... this new generator 
is so great, but i did think i'd get more than 5-6 gallons from one 
set of silver rods... please give me some indications as to 
what 'normal' is where the lifespan of the silver rods are concerned, 
as i certainly don't want to be throwing them out if there is still 
life in them... but, i don't want to brewing stuff for 45 min. just 
to get the ppm up either... i know that i must certainly invest in 
a 'pwt' meter, and will do so as soon as i can come up with the 
funds... you're input is greatly appreciated as always... in advance, 
thanks! deb