Posted: Mon May 02, 2005 6:43 pm
100 liters is roughly 26 gallons (about 3.785 liters is one gallon). How big are your turtles? They must surely be more than an inch long (shell length) if they're growing and, if so, you should be thinking of upgrading already. (Rough guide for container size is to allow 10 gallons of tank/container per inch of shell length.)
The plastic container is OK for two really small turts, but as they increase in size, you'll want to increase the water depth (how deep is it now?), and the plastic will bow out on the sides. After a cleaning you also may find that suction cups don't stick as well for a while (depends on what the container is made of).
I started out like you with a plastic container about your size. From there I went to a 50 gallon Rubbermaid storage container, which had it's own problems. Finally I started using stock tanks (you can buy them at feed and grain stores and stores like Tractor Supply Company (do a web search to find its homepage). Stock tanks are sturdy, meant to hold water, durable and easy to clean. I recommend them.