I need help too.
OK, I am not a pond newbee but new on this forum.
My wife and I have had a 600 L cement Koi pond for 30 years or more.
We used to have lollies and just let the pond biota balance out naturally with a few plants like lilies to reduce sunlight.
However, just over a year ago, we installed an Aquapro all in one pump filter after a major cleanup of the pond.
Well, the lilies failed to thrive this time but the Aquapro kept the water pretty clear with many filter cleans.
However, this summer it;s not doing well at all. The filter is blocking up really fast and needing a clean twice a week and the water is very opaque green now. It's a sponge filter so not capable of removing single cell algae. The PH and nutrients are good but the algae bloom is out of control. The pump has a UV lamp which I thought may have failed. The lamp appeared a little discolored but the filaments looked OK. So, I tested the lamp with an ohm meter which indicates the lamp is open circuit. I got a replacement lamp which also test open circuit. Well I'm not familiar with uncoated filament UV Lamps so, don't really know how they work or want to expect. So I then exposed some fluorescent materials to the lamp, being exceedingly careful to shield myself from the direct UV.
The materials failed to fluoresce. So it appears the lamp is not producing UV. Without a clear way forward, I put the pump back in the pond in hopes I am mistaken but alas, there is not improvement with the green water. The pump is out of warranty so it seem to me there is no chance of getting anyone to repair the pump. So, it's going to be up to me to diagnose and repair. Problem is, I haven't been able to find out how it's supposed to work. I know the supply is 12 V AC but the Watts and Amps for the lamp suggest the the voltage should be twice that and the filament resistance should be measurable (according to ohms law). Also, I don't understand what makes a filament lamp with clear glass envelops emit UV if it's just 50 Hz low voltage AC. Perhaps it's driven by very high frequency AC? So, none of this is making any sense. Can anyone enlighten me as to how this is supposed to work?
I don't think it's acceptable to have to purchase a new all in one filter pump every year.
PS. We have not been able to source any water lilies, possibly due to the severe drought this year.
PPS, I found the lamp has a cutout switch that is engaged when the lamp cover is in place. This explains why I detected no UV in my test as the switch was not engaged. With it engaged, I find 1860 V supplied to the lamp. High voltage yes but current limited. This explains the lamp's high resistance. With the switch disengaged, I get 3.5V at 68 kHz. I haven't tested the frequency at high voltage as I don't want to risk my meter. I assume this means the filament is excited by high frequency/high voltage AC to emit UV. I still don't know if these measurements are in spec but at lease making some sense now. Also found the new lamp has a little discoloration, so obviously been getting hot. I'll assume the lamp is working for now and just see what happens to the pond over the next week.
The manufacture has not responded to my request for assistance.
Ken
OK, I am not a pond newbee but new on this forum.
My wife and I have had a 600 L cement Koi pond for 30 years or more.
We used to have lollies and just let the pond biota balance out naturally with a few plants like lilies to reduce sunlight.
However, just over a year ago, we installed an Aquapro all in one pump filter after a major cleanup of the pond.
Well, the lilies failed to thrive this time but the Aquapro kept the water pretty clear with many filter cleans.
However, this summer it;s not doing well at all. The filter is blocking up really fast and needing a clean twice a week and the water is very opaque green now. It's a sponge filter so not capable of removing single cell algae. The PH and nutrients are good but the algae bloom is out of control. The pump has a UV lamp which I thought may have failed. The lamp appeared a little discolored but the filaments looked OK. So, I tested the lamp with an ohm meter which indicates the lamp is open circuit. I got a replacement lamp which also test open circuit. Well I'm not familiar with uncoated filament UV Lamps so, don't really know how they work or want to expect. So I then exposed some fluorescent materials to the lamp, being exceedingly careful to shield myself from the direct UV.
The materials failed to fluoresce. So it appears the lamp is not producing UV. Without a clear way forward, I put the pump back in the pond in hopes I am mistaken but alas, there is not improvement with the green water. The pump is out of warranty so it seem to me there is no chance of getting anyone to repair the pump. So, it's going to be up to me to diagnose and repair. Problem is, I haven't been able to find out how it's supposed to work. I know the supply is 12 V AC but the Watts and Amps for the lamp suggest the the voltage should be twice that and the filament resistance should be measurable (according to ohms law). Also, I don't understand what makes a filament lamp with clear glass envelops emit UV if it's just 50 Hz low voltage AC. Perhaps it's driven by very high frequency AC? So, none of this is making any sense. Can anyone enlighten me as to how this is supposed to work?
I don't think it's acceptable to have to purchase a new all in one filter pump every year.
PS. We have not been able to source any water lilies, possibly due to the severe drought this year.
PPS, I found the lamp has a cutout switch that is engaged when the lamp cover is in place. This explains why I detected no UV in my test as the switch was not engaged. With it engaged, I find 1860 V supplied to the lamp. High voltage yes but current limited. This explains the lamp's high resistance. With the switch disengaged, I get 3.5V at 68 kHz. I haven't tested the frequency at high voltage as I don't want to risk my meter. I assume this means the filament is excited by high frequency/high voltage AC to emit UV. I still don't know if these measurements are in spec but at lease making some sense now. Also found the new lamp has a little discoloration, so obviously been getting hot. I'll assume the lamp is working for now and just see what happens to the pond over the next week.
The manufacture has not responded to my request for assistance.
Ken
Last edited: