Green water problem

[Deano]

HI
My pond was doing really well - its been established a long time. a couple of the fish were sluggish so we tried a partial water change 1st I forgot to turn off the UVA lights before I turned the pumps off -would I have caused damage to the UVA lights ?
We took about a foot of water out and replaced it with hose water and hoovered the bottom - the pond was still really clear
Over the week it has gone very murky and I cant see my lovely fish - its so green and the algae is floating on the top
Can anyone please tell me how to rectify this
I haven't used any chemicals - I have cleaned the the two filters -
The pond is 17 ft long 8 ft wide and 4 ft deep -concrete built - established 15 years approx 6500 gallons
I have 18 to 20 large koi some 2ft long all big though
I feed them pellets in the morning - some greens peas, lettuce in moderation then some more pellets early evening


Thanks in advance of your help
best regards
Dean

 

[dieselplower]

Can you describe how thuroughly you cleaned your filters and can you tell if your UV bulb is still working? It would also be helpful to know your Ammonia, Nitrate, and Phosphate numbers.

 

[Deano]

Hi - I took all of the brushes out, cleaned them off in water wiped the drum out then put them in - its hard to tell if the bulb is working - it is glowing but its about 12 months old
I haven't tested the water levels - sorry

 

[dieselplower]

No problem. At 12 months old, it is safe to say the UV bulb is no longer effective.
If you gave the brushes and drum a real good cleaning in chlorinated water, it would kill off some, or even a lot of the bacteria that break down ammonia and nitrite in your pond. Algae use those things for food. So if you killed some of them off, the remainder can no longer process them fast enough, so the algea multiplies.

 

[Dave 54]

We always clean our brushes by hand in water from the vortex that is about to be vioded to the drain give them a good rub with your hands it should clean them of everything on them in one .
When was the last filter clean we normally prtesure wash our filter material dont worry it wont kill the bacteria off just take off the top layer thats all .
We then add Microbe_lift PL filter pad innoculent gel to the filter pads (follow the instructions on the bottle .
You feed twice daily yes Deano how much feed do you give I recopomend only what they will eat in 5 minutes take any residue out
UV-C's loose about half their power over six months you should in reality change them then but thats up to you .
You could try TAP algae pads they would help you rid the pond of algae but your going to need a few I think its 2 per 1,000 gallons imperial they are very good at what they do though :-

http://www.seapets.co.uk/products/p...n-water-clarifiers/tap-algae-pad-1000gal.html

One thing nobody has asked what are your water perameters please Ammonia, Nitrite, Nitrate, Ph, Gh, Kh please .


Dave

 

[Deano]

Hi Guys,thanks for your advice
I went to the aqua cntr today and had a sample of water tested - they didnt give me specific readings but did say that my water is spot on
My fish eat all food within 5mins so im pretty sure that im not overfeeding
I have replaced my UV lamp today so hopefully it will impact soon
I will take care not to use chlorinated water in the filters again

Would it benefit my pond to give it shade?

Thanks and regards
Dean