I got a couple of these MTS from my local PetSmart for free. I asked for 6 but instead they gave me 10. It's been over 5 months and all I have left is 596,734 babies and counting . The clones take forever to grow.
I find that you won't notice when the population explodes as they will be hiding in the substrate most of the time, I thought I had maybe 20 in my 10 gallon, but when I re-scaped it, I counted out 250 before I decided that counting one by one was really lame and I couldn't be bothered to collect more of them from the mud that was my substrate.