Question
This is my first pond. I need some advice please. I have dug the hole put the liner and added gold fish, Lilly's, Cattails,and other plants to my pond it has two areas where water trickles in to it it is 4500gl. I put in three pumps for the pond one for the large area and one for each of the falls at the end of the pumps i have put home made bio filters. I need to know what kind of biofilter w/ UV light too buy with out spending a tun. also if i need an aerator if I'm going to put KIO? And cane I put turtles in yet?Also is a PH tester the same for a pool than for a pond? I'm scared too kill any thing. I need all the advice you could give. I think I bit off more than I could chue.Thank you  

Answer
If you already built biofilters yourself, I'm not sure why you need to buy another one?  I don't use UV lights on my pond.  For a balanced pond with plants, you don't need one but they keep ponds without plants much more clear.  I don't have enough experience with them to suggest a brand.  Your waterfalls provide aeration.  You may need more aeration during the summer if the pond is really warm, and there are too many fish.  Orfe need the most oxygen and then koi and then goldfish and native fish.  Turtles will nip at larger fish and eat smaller fish but many people keep them with koi or in other sorts of ponds.  As long as you don't mind them eating some plants and animals, it's fine.  A pool pH test kit will work fine for a pond (don't get the chemicals in the pond) but the pool pH test kit normally has a range that's ideal for the pool which may not be the range your pond needs.  Most ponds need a pH of 7 to 8.  These pages on my site may help.  Good luck!

http://www.fishpondinfo.com/plants/uv.htm
http://www.fishpondinfo.com/koi.htm
http://www.fishpondinfo.com/turtles/turpond.htm
http://www.fishpondinfo.com/chem.htm