How Do I Clean The Water In My Fish Pond?

[Mobi]

I know this subject has come up before, but I can't recall accurately the solutions.

My fish pond is around 4 meters by 1.5 meters, and 1 meter deep and has around 15 koi carp living there for the past 2 years or so. None of them ever die, but I rarely see them as the water is so green and murky.

The pond is in full sun light for several hours a day, and I 'aerate' it with a water pump and filter, ornamental fountains , and a waterfall for around 6 hours a day.

There are no plants in the pond.

I drained the pool once, cleaned it out and replaced with fresh water, but within a week or so the water was 'dirty' again. It was quite an operation and involved using an external water pump, catching all the fish and keeping them for 2-3 days in bowls, and then replacing the water with well water trucked in. Quite an operation that I don't wish to repeat too often.

I have seen fish ponds in Thailand where the water is crystal clear, and was wondering how it is kept like that.

Any advice would be appreciated.

Thanks

Mobi

[Nienke]

If I'm not mistaken, they have been talking about this in detail in the following thread:

http://www.thaivisa.com/forum/index.php?sh...fish+pond+water

Nienke

[ignis]

My fish pond the water is crystal clear, I have 94 Koi........ 12 Ballon Fish, loads of Frogs [NO plants in the water but on top of pillars just out of the water.. found the Koi will eat the plants]

I do have a VERY large flat stone slab on top of some square bricks..... if the sun is shining straight on the pond the fish hide under the slab.

Self made waterfall, on timer 7am - 7pm

6 Port Air Filter, on timer 8x for 1 hrs over 24

2x home made water filters. 1x on 24/7 the other on a timer for daylight hours....... The VERY large square rubish bins 1m x 1m x 1m high with lid, [if you make yourself don't forget to put in a drain plug at the bottom]

I have 3/4 filled these with Coral/Laver stones, then laid the white fiber filter [buy in 4m rolls] on top, the water is pumped into the top and goes back into the pond from 3/4 of the way down...

You need access to the bins, but they do NOT need to be in or anywhere near the pond, so easy to hide......... I take out the white carbon filter every 2 days and wash with the hose untill white again....... I change these fiters every month + take out the drain plug and wash the stones every 6months..

The Pond is now 4year old and crystal clear, I DO NOT add anything to the water........ 2 fish have died in 4 years!!!

[Tywais]

There are no plants in the pond.

The algae thrive on the Nitrogen in the water, reducing/eliminating that will stop the growth. Water Lilies are very good at 'eating' the Nitrogen. Also there are biological filters (active) where a certain type of bacteria is introduced to also 'eat' the nitrogen. Another method is UV filtration, though this can be expensive and complex to setup. Combine one or more of these with shading the pond from direct sunlight should stop it.

[Naam]

Another method is UV filtration, though this can be expensive and complex to setup.

tried it, spent nearly 35,000 Baht on it, no result at all. stupid me then played around with algaecide. result = all kois dead and a variety of other fish dead; four unkown species survived. changed water completely, pond after 10 days green like pea soup, now clearing up nicely, thick layers of algae depositing on bottom and rocks, filter pump and waterfall OFF since changing the water. waiting patiently what happens next.

[tuffy]

I am interested in the answer to this as well. My wife has taken over a restauant with a quite large Koi pond, waterfalls and fountains. The previous owner has neglected the maitenenance and they are using oyster shells as the bio filter but no fiber filter. My question is do I need to replace the water and clean the whole thing which would include putting up the fish, bringing in a water truck, etc, or can I filter the existing water with a new set of filters?

[Gary A]

Buy a swimming pool sand filter. Don't be cheap and buy a real small one because it will need backwashed every five minutes. They have a pressure gage that tells you when it needs backwashed. Algae will clog it in a hurry but gradually the water becomes cleaner and the filter will run longer. When you can run the filter for an hour or so the water is clean until the next time. It really works pretty good unless you allow the water to go VERY green.

[ignis]

By the way my Pumps are NOT the cheap 'Supermarket' ones....... I bought them all at the Fish Wholesale Market & Supplies 6,500 baht each.. 1 1/2" pipes......... as all the water is changed/filtered at least twice a day it is impossible not to have a crystal clear pool

I drive down to the Market every 6 months [2hours drive away] also buy the Fish food there [big sacks 400 baht] Koi are 20 - 60 baht each, the very 1st ones i bought there are now very large as now 4yrs old..

[Mobi]

Some interesting stuff here. Thanks.

I'll let you know how I get on.

Mobi

[milesm]

Some interesting stuff here. Thanks.

I'll let you know how I get on.

Mobi

your pond is getting too much direct sunlight. perhaps you could put a filtering screen (50%+ blockage) over parts of your pond.

water lettuce and water hyacinth will provide shade and food, as well as take up excess nutrients in the water, as an earlier post suggested.

good luck.