My four koi and half-dozen goldies all survived the winter. I can see them hanging about 18" below the pond's surface. My water temperature barely touched 46 degrees today here in Northern Virginia (zone 7). So we have a couple of weeks to go before the spring magic begins ... I followed the link to your pond photos, JPinard. Your pond is beautiful!

Check your 'in' tube. I have been having issues with string algae building up right where the water should be entering the bio filter. I have been taking care to clean that area every week when I change my filters. You may be getting good flow for a brief time, as you turn off the pump. If there is a buildup it may dislodge itself when the pressure of the water pushing on it stops. Then when the water flow begins again, it plugs up. Good luck.

Everything I have done with Savio has been worth the money. Their skimmers are more expensive, but the bells and whistles make them a better buy, specifically if you want a UV they are cheaper than a inexpensive skimmer with separate UV. But that isn't the question is it. I've heard of a few people changing pools to ponds, not many successful ones, but some none the less. Hooking into an existing bottom drain would always be ideal, especially if you are going to have large koi. I wouldn't want to try it myself, but it would be the best way if it could be done. I've had a lot of customers have bad experiences with the online sales, but there are some good deals, but there is risk. The Danner 4800s are very reliable and efficient pumps, and there will be some price differences with those. If you see any Savio price differences I would advise against that site or store. Savio has an extremely strong rule of one retail price and they punish those that change them. If they are selling cheap online, chances are they aren't on the up and up.

Is there an intake screen over the intake? If not, you could put some type of screening over it. As long as the pump doesn't overheat due to you restricting the intake of water. We use mesh laundry bag over our pump's intake (over a plastic crate, to avoid restricting the flow), but little tadpoles might get through the openings. We do it to keep the water hyacinth roots and goldfish out. :) Mary