As they have mentioned it is normal. Do not add any fish to the tank. I cycled my tank with my Betta Clark and he is fine. It was cloudy for a week so I would do daily 10% changes(use your gravel vac on the gravel each day so to get the extra food that drops. Do try to leave dome debris though haha).
When you set up a tank, atleast this is how I do it, I never change the filter cartridge/media for a month and a half. LEt the bacteria grow before you change it. It will estblish itself in the tank and then it is safe to replace the filter media monthly.
The tank will probably be cloudt for about two weeks. It took two weeks to cycle my tank and Clark is doing great! His tank is now crystal clear, beautiful water! And Algae is not growing out of control(yet). Once the wate ris clear start adding quarium salt and it (should) keep the algae under control. If it gets too bad a 10 gallon is big enough for a snail to eat the algae