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Re: Help! My pond fish keep dying.

Subject: Re: Help! My pond fish keep dying.
by 2010 on 30/5/2012 20:20:38

Bluechild, OldMrGrumpy is not wrong.

But ideally you should know why what you have does not work, not just the fact it does not work.

I came up with a slightly different figure for your pond volume (it really was only slightly different) so lets split the difference and say your pond is 2000 Litres.

I was hoping you were going to say the pump rate in LPH not LPM, then it would be more apparent.

Your pump 5,000 LPH
Your pond 2,000 Litres

Do you see where this is going?
Being realistic the pump will only pump 5,000 LPH at zero head, so lets say 4,000 LPH at what ever head you have.

So that means your pump can send the whole of your ponds 4,000 litres through the filter twice every hour.

Most koi pond owners (with a reasonable stock level) send the water through their filters once every two hours. So yours is going through 4 times as fast as the max, ideally you should be aiming for once every 4 hours.

Your filter itself has lots of capacity (it could be argued its too big (it is if you read the specs)

? Suitable for ponds to 15 000 litres (3000 gallons).
? UV Rating: 13W
? Dimensions: L x W x H = 390 x 280 x 430mm (15.5? x 11? x 17?)
? Maximum flowrate: 7500 L/H (1500 GPH)
? Pond size: 3750 - 15000 Litres (750 - 3000 Gal.)

You can never have too much filtration, but the flow rate can be too fast.

In short, the good bacteria in your filter do not have enough time to do their job. I would be inclined to buy a couple of box filters and connect them in series, (or a very big box filter) so it gives the bacteria more time.
The Neptune 5000 is a feature /fountain pump, not a filter pump, perhaps you may want to change that too. (but for the time being you could turn its flow rate down.

One more thing, you need to get yourself a test kit, so you can test the water on a regular basis yourself. (Some one here on the forum has mentioned a good place to get them, try a search)

And finally, shops are there to make money, forums are here for advice.

Good luck and please post a picture of your pond.