Hi and Welcome Yoda to the Turtle Talk Forums, Being from Canada, I assume that Canada goes by Great Britain's overall measurements in liquids being that the Queen of England is head of State. With that stated, I added below my post the conversion link in which you can see that 1300 liters equals to 286 rounded off. Feel free to check it yourself below.
Now the general rule of thumb according to most people is 10 gallons of habitat for every inch of shell length. So say you have two red ear slider females that can get 12 inches long however they tend to grow 10 to 11 inches but lets go with say 12 inches maximum. 1 red ear female slider would equal to 120 gallons so two adult females would be 240 gallons using this rule of thumb.
Being that your area would be a hair under 286, you are fine and correct keeping in mind as Steve pointed out that the turtles get along. Steve has also mentioned that Canada has some inconsistent laws regarding reptile keeping. I found this out to with the permits needed to ship reptiles in and out of the Countries. Steve and others on these boards have recommended to check your local and government laws to stay legal and I also agree with them.
Here is the conversion link for liter to gallons (UK)
http://www.thecalculatorsite.com/conver ... allons-(uk).php