nitrate levels

[hacnp]

Our pond has been running with a nitrate reading of 10 to 15 PPM for a year now. This is as low as I can get it to go with a 15 GPH flow thru in warm months and a shower filter running 4500 GPH year round on a 12500 Gal. system. Vortex flushed daily warm weather and twice a week in winter. Fish load is 15 fish, 3 less than 10", 4 less than 20" the rest 20" to 27". Feeding a mixture of OSI 168 and Rangen with some High Silk during the warmer months. Generally feed twice a day when water is above 65, tapering off with cooler temps.

Two questions, one is there any thing else I can do to lower the reading? Two, what is typical for others here?

[jomoma]

at this level your fish should be dead. You need more gph. that is the core of your problem.

[KoiCop]

Hello hacnp . . .

I doubt that increased turnover would lower nitrates any further. To do that, you either need to remove the organics from the pond before they're converted to ammonia, nitrite then nitrate OR increase your flowthrough to flush the nitrates after they've been produced. Or both.

I water change out 10% + water per day on an overstocked 6K gallon pond -- and my nitrate level runs in the 5-10 ppm range.

Best wishes,

[jomoma]

4500 GPH year round on a 12500 Gal. system. Vortex flushed daily warm weather and twice a week in winter. Fish load is 15 fish, 3 less than 10", 4 less than 20" the rest 20" to 27". Feeding a mixture of OSI 168 and Rangen with some High Silk during the warmer months. Generally feed twice a day when water is above 65, tapering off with cooler temps.

Two questions, one is there any thing else I can do to lower the reading? Two, what is typical for others here?[/quote]

If you are flushing your filter system daily then organic build up mite not be your problem. Increaseing you gph can only help. Maybe you are feeding you koi to much.?

I see that you could fix your problem with one or more of these solutions. Increase your gph. Increase your filter size- to have more surface for your bactiera. Feed your koi less. Sell some of your koi. Or and maybe you need more airation for your fish and bugs.

[jomoma]

ok nitrate

[cmungo]

Have you tested your source water and what test kit are you using?

[moikoi]

the three biggest ones about 22-24". i test for nitrate about every 5 months. i always get a 0 reading.

[hacnp]

Thanks for the replys, Getting the organics before decay, thats what I thought daily cleaning would do. Maxed out there.

Water changes, our well will not support a higher flowrate, in fact I have taken to running it only in warmer seasons due to drought in the area, central North Carolina. The water tests at about one half of one PPM or so of phosphate and no nitrate with Aquarium Pharmaceuticals tests.

I do plan on culling 3 fish this spring, I had also wanted to increase feed rate for the remaining fish during the 100 days of summer to 4 or 5 smaller feedings with a probiotic food mix in hopes of better growth.
As to air, the pond has two spindrifters. I run 90 Liters an hour total now, afraid to go higher because I might rupture the membranes.
With the drains and the shower I think I am near saturation but dont have a ox. meter or test kit.

Any other ideas? BTW setup is all gravity, no pressurized filters.

[hacnp]

Quote: Originally Posted by moikoi the three biggest ones about 22-24". i test for nitrate about every 5 months. i always get a 0 reading.

Could you describe your filtration and water change routine? I would love to get any improvment I can.

[RogerL]

A pretty fundamental question first (didn't see it above):

What do your ammonia and nitrite tests read? Even see elevated nitrites or occasional spikes?

You talk about a shower filter and a vortex. Is the shower all you have for biological?