Hi All

I am new to koi - this forum has helped me a lot since I inherited a koi pond. I have gained a lot of interest in koi and koi keeping.Thanks for all the members advice - so far!
I purchased a new house - with a existing koi pond. The more I read here - the more I realise the pond was not designed well. No bottom drain – I have a square form of a polly pipes (50 mm) with holes and slits in.
I have a 12 000L pond, 4000L top pond that flow into a 8000L big pond. I have replaced the pipes with proper blue PVC pipes. The pipes was 40mm polly pipe.
My filter setup is as follow -
.75KW pump - pond to 2bag sand filer (with new koi sand) to 2bag sand filter filled with 500 boi balls - to 1.2m, 3 tier water fall to pond.
I want to add back the 55w Ultra Zap UV. Where is the best place to fit the UV ?
1) before my sand filter ?
2) between my sand and Boi filter ?
3) after my Bio filter ?

Many Thanks !
Eugene

At the end where you have clean water.

Ek sekondeer met Marius...

Hi Eugene

After your bio filter, remember to install it such that it wont run dry, the globe should always be under water.

Also try to connect the wiring to your pump. You can have a switch for the UV to switch it on and off but take the power from the motor output. When ever you switch motor off the UV will be off as well. With the second switch you can switch uv on and off whenever you like.

exactly as Marius has said. I have mine connected to my pump mains so that when the pump is off the UV is off as well, then have a on\off switch at the UV itself for me to switch on\off when I so chose.

You will need to add the UV after your bio filter just before the 3 tier waterfall

Why should a uv light be covered in water all the time ?

Jaco ek ken daai antwoord ,deur duur ondervinding geleer .As die tube aan is en droog is, word hy warm, sodra water weer oor hom loop disintigreer die middelste stuk van die tube, siedaar een duur bulp verder en jy het weer n UV

Nee ek bedoel kan 'n uv werk sonder om in water te wees ?
Antwoord is ja, het myne al bo my settlement chamber gehad, werk net so goed.

Die bulb van die Professional UltraZap Uv lig kom glad nie in aanraking met water nie

Hi Jaco ek het nie n tegniese antwoord ek glo dit is nie n probleem vir hom om te brand sonder water, maar soos CJ se as hy aan is en kry water dan gaan hy bars. Dit is maar glas ne.

Bobby. Ek ken nie daai UV as ek weer UltraZap toe gaan dan sal ek tog kyk hoe hy werk.

Ek weet dat die biltong maak manne gebruik ook n tiepe UV om te verhoed dat die biltong muff. en hy werk beslis sonder water.

UV lights operate optimally at 40C. The amount of effective UV emitted at this temperature is about double that at 20C. Hence, the Professional UV tube sold by Ultrazap which is enclosed in a quartz sleeve is identical to the standard unit but because of the quartz sleeve the bulb reaches a higher temperature.

Thank you all for your advise. I have read the green / brown alge (in the water) is so small that your sand filter wont trap them all - you should add the UV before your sand filter - when the UV kill the alge , the dead alge will cling together enabeling your filter to trap them better. Some of the diagrams I have seem also show the UV before the filter.

Anyone's thoughts on this ?

Hi Eugene

No way's can you place a normal UV sterilizer before the Sand filter. it is not designed for the pressures created in front of the filter. And there is no way it will kill the algae and clump it in that time and distance, it takes to enter the filter.
The Sand filter, if it has the correct koi sand or zeolite and fitted with the correct fingers will definitely trap all the solids you can send there.

I agree, the back pressure that builds up between the pump and sand filter is too high for a UV. The UV should be the last item in the line apart from a venturi.

Thanks - I will do the mod this weekend - will add the UV after my Boi.

also you always have little stones and other debris that ends up in your pond that gets sucked in via the bottom drain, which means if your UV is first in line it's going to come in contact with your UV which means you'll be replacing globes every second day.