Yes a UV filter safe for your turtle. Many people swear by them but if you have proper filtration and maintain a good regiment for water changes and filter cleanings they aren't necessary. I've got a submersible UV filter that is sitting in a bin somewhere in storage. No need to use it. No desire to change the expensive bulbs out every 6 months. It's cheaper and easier to just get a proper sized filter and take care of it.
Here's our reccomended filter sizings and media setups:
viewtopic.php?f=9&t=30145That aquatop canister filter is WAY too small for a 200 gallon turtle tank. 525GPH is from the pump with no media. When you fill the canister with media and add the head pressure from the height of the hoses you're probably at about half of that rating or less. On a 200 gallon tank, you'd only be turning the water over once an hour. 3-5x per hour turnover is ideal.
For example, a Fluval FX5 is rated at 900GPH at the pump. With media it's rated at 607 if memory serves me. Add in head pressure and you've got probably 500 GPH. We suggest no more than a 150Gallon turtle tank for an FX5.
The truaqua pond filter you linked is interesting. I haven't seen that one before. IF the specs match what the filter actually does then that's a much better fit for your tank. The question is how much media capacity is lost due to the space taken up by that UV sterilizer? Having a large quantity of bio media is key for turtle keeping. I would be more inclined to get that PFS300 for $50 more.
