uv lights revisited.

[leo]

Good morning! On April 13 I posted a question about UV lights. First I want to thank you all for the very helpful information. My calculations on my pond gallons were way off.So I have a revised question. Our pond is actually 3200 gallons. Heavy fish load approx 40 koi and gold fish from 18 inches down to 6 inches. As I stated before we are having a fish give away, we plan on keeping 20 of the larger koi and goldfish. We have a laguna 2100 and now I'm using a 1240 gph pump 1.5 inch flex pipe approx 18ft from pump to filter and filter to waterfall approx 5 ft.I brought a new filter Go Plus Bio Filter rated for 2500 gals. Running a 3200 gph pump 1.25 inch flex pipe..10 ft from pump to filter, 5 ft from filter to waterfall.Waterfall is approx 3 ft above water surface. Avg depth of pond 2.5 ft. Water test came out good expect for Phosphorus did a 25% water change will test again today.Water is starting to clear up, filters have a total of 33 watt UV which I intend to turn off when water clears a little more. Question is do I have enough filtration?. Also the Go Plus filter will handle up to a 4000 gph pump. I also have a Air Pump Kit APK100 rated for 5000 gals. Thanks guys!

 

[LarryM]

That's seems like an aweful lot of fish for that size pond. I have a 15,000 gal with 13 koi and maybe 20 goldfish. I wouldn't think of adding more koi. The problem with koi is they outgrow the filtration system. Let me relate my past experience with you. We bought our house 12years ago and it came with a beautiful 15 x 30 inground pool which we never swam in much. I decided to turn it into a koi pond. I was thrilled to have a pond this big and promptly went out and bought around 35 koi from a koi seller as a package deal to add to the 40 or so goldfish I already had. My water instantly turned green and I scrambled to buy the proper filters etc. Nothing seemed to keep the water clear until I installed a 240 watt UV system. The UV was the magic I needed. All was good and perfect for the next two years as I watched my koi grow in crystal clear water. In the third year problems started happening one after another until I lost almost all of my fish. I'll skip all the gory details but the bottom line is those koi grew to a point where they were produced more waste than my bio filtration could process. And the problem was hidden from me by the UV which kept the water clear all the time. Now I only have 13 koi and I know that when they approach 30 inches or more my filter can handle it and still have capacity to add other fish like goldfish and bluegills. My water stays clear on its own and I only use my UV a couple times a year if the water starts to turn green.
Moral of the story is too many koi can be a ticking time bomb ready to go off in slow motion so you may even know it's happened until it's too late.

 

[Stephen Noble]

Agree with Larry, you have (and will still have) too many large Koi for that size pond. Regarding your pump...try to have a water turnover rate at least 1 1/2 to 2 times per hour. Here is a little secret about pump and filter GPH. Filter numbers are for new equipment with new filter media. New pumps are rated with no load (unless stated otherwise) meaning, a new pump running with nothing connected to it. Once you add plumbing, especially plumbing with angles and couplings and then add in head height your GPH (and turnover rate) goes way down. By the way, welcome to the forum!

 

[Tula]

I agree about your having too many fish in your pond, that's a high fish load.......even having 20. I think you should turn your pond water over at least twice per hour and with your high fish load, I'd use the 4000 GPH pump you mentioned.

 

[Jimmy Gibson]

I won’t tell you the whole story..... but you have about 4 times too many fish.....I have a 3000 gallon pond with excellent bio-filtration system, so good In fact I had almost as many fish as you have...... and everything was great while the water was warm....the bacteria was eating the ammonia, all the plants I have was taking care of the nitrates......everything was great until the temperature dropped......that’s when the bacteria died away, the plants hibernated for the winter. So my pond crashed, I lost all but two fish, I now made it through the winter and this spring with eight beautiful fish......Although I do check my water periodically..... there is really no need to its always perfect......now my problem was first year ponder enthusiasm and lack of knowledge. But don’t mean to be harsh but You have too many fish....