Help Needed Re Pond Filtration

[Dave the Dude]

Hi guys

I am a cheap Charlie pond owner in need of some cost effective advice from the experts.

Please do not suggest expensive elaborate solutions as unfortunately they will be beyond my

Capabilities.

THE POND SYSTEM

My wonderful wife had it built when I was overseas and I do realize its not a good shape for water circulation.

Its ‘S’ shaped with the equivalent of a one metre by 13 metre length and a flat (tiled!!!) bottom giving a uniform

water depth of 50cm.

I have a submersible pump running 24/7 to a good sized UV light/filter (14ins) then into a ‘home made’ filter box.

Water is pumped in the bottom of the box then goes though stones/charcoal/stones & then small plastic media.

After that it runs down a small waterfall back into pond. The box is approx 60x50cm & 40cmdeep. I have tried to

shade the pond and have lilies/floating water hyacinth plus a couple of other reed type plans. I occasionally use

a second pump for extra aeration.

THE PROBLEM

Unfortunately, I have recently had all 6 big (12>14ins) Carp die and the water is a beautiful shade of ‘Pea Soup.’

There are still smaller fish surviving (10?) and whilst I do not need/expect a show pond, I would like a half decent

Environment for the fish.

Obviously it’s easy to criticize the cheap nature of this, but I hope someone can give me some sensible & ‘do-able’ advice

Thanks

Dave

[allcladrad]

Just a couple of thoughts, Fewer or smaller fish, might add a few pla nin (tilapia) they are algae eaters, snails help also, the ones you see at the wet markets are fine, shade or plant covering the waters surface, the sun is the big factor in algae production.

Those are the cheapest ideas, increasing your filter size would be the expensive one.

The pla nin will eat plants if they don't have enough algae to eat, so I would add a few at a time or put in a couple of dozen and be ready to thin them out. I get mine at about an 1 1/4" in length, to small to eat plants, yet large enough to eat algae. If you don't feed them they will be slow growers, a good thing.

[macb]

I dont know a thing about ponds but I like to try and help folks on here.

I have looked on the internet and found some advice links for you

http://www.koi-fish.co.uk/acatalog/pond_algae.html

http://forums2.gardenweb.com/forums/load/p...1138009480.html

http://www.practical-water-gardens.com/blanketweed.htm

I did a quick scan there is some guidance there on chemical biological cures hope these help.

[jackr]

I'd say your filter is too small and the wrong type - read somewhere that the surface area of the filter should be about a third of the pond's. In your case I understand that'd be huge but you do have a large pond and a small filter would really struggle. You could try the biofilter approach as opposed to/or including mechanical. While you're probably helping to remove the larger sediments, you also need bacteria to feed on the algae, as they do in the wild. Doubtful the UV light would remove it all. A biofilter will have something like pumice at the bottom, brushes in the middle, and scouring pad-type filter media at the top. Then bung in some beneficial bacteria (obtainable from places that sell fish) to kickstart it. The pump should be man enough to move the entire pond volume in 3 or 4 hours - about 2000l per hour in your case. Be sure to place the pump at the opposite end of the pond to the filter.

[burman]

Water is pumped in the bottom of the box then goes though stones/charcoal/stones & then small plastic media.

Don't wash these out in tap water, or leave the pump turned off for several hours, it will kill the bacteria in the filter which helps clean your water.

How many times do you feed your fish a day? Once a day is fine, every few days may be advisable as this point. Less food, less shit, less pollution.

What's the power of your pump? If it's not strong enough then you need a larger one.

For the green water effect you can counteract by adding more plants to the pond, they will starve out the algae that makes the green water.

Impossible to know why the fish died without checking the water conditions for at least, ammonia and nitrite. 9/10 times it is usually bad water conditions that kills fish, though your pond is very shallow also, possible the water temp got too high?

[Matan]

Water is pumped in the bottom of the box then goes though stones/charcoal/stones & then small plastic media.

Don't wash these out in tap water, or leave the pump turned off for several hours, it will kill the bacteria in the filter which helps clean your water.

How many times do you feed your fish a day? Once a day is fine, every few days may be advisable as this point. Less food, less shit, less pollution.

What's the power of your pump? If it's not strong enough then you need a larger one.

For the green water effect you can counteract by adding more plants to the pond, they will starve out the algae that makes the green water.

Impossible to know why the fish died without checking the water conditions for at least, ammonia and nitrite. 9/10 times it is usually bad water conditions that kills fish, though your pond is very shallow also, possible the water temp got too high?

Green water can cause pH swings but this is normally just uncomfortable for the fish, rather than lethal. I agree that the likelihood is that ammonia/nitrite/nitrate may have killed the fish, or the temperature. A 60cm pond in the UK can be noticeably affected by temperature so a 50cm pond in Thailand could quickly become very hot. When water is warm it can hold less dissolved oxygen and this could have killed the fish too. I would advise anyone building a pond in Thailand to either shade it heavily, or make it deep!

[fazbender]

Hi

It does sound like it maybe a problem with ammonia/nitrate levels but other fish surviving?????On the whole green water will not usually kill koi if the chemical levels are ok 0-ppl ammonia and around 8-9 ph.In fact koi do like this type of enviroment,they can only see up to one metre anyway.Its just we like to see them.

So the first thing to look for in any pond that has direct sunlight and high green algee content is to check ph levels and ammonia, watch the fish and see if they come to the surface and suck in air. This means low very low oxygen levels and/or high levels of bad chemicals,STOP FEEDING AND DO a high percentage water change. My pond is 2400 gallons and everymonth I change 1400 gallons this is plus watering the garden everyday from the pond attached to a high powered pump so this is about 10% new water everyday. My pond is in direct sun for about ten hours. Yes I do have algee problems but it has to be dealt with,I have never lost any of my koi or any of the other types either for that matter.

I have built a biofilter and run two pumps that shift 220ltr per/min, inside the filter the two pipes from the pumps face each other and that creates oxygen as does a drop of 400mm to the pond. A pond needs OXYGEN AND PLENTY OF IT. Your pond does sound like its too shallow so you have to work out a way to get the water moving and trying to cool it down.I would suggest making the water fall higher and put some smaller pumps that can spray water across the surface of the pond.In temps like this still water is a bad thing. You can also put in more water lilies or other plants in general to take up the chemicals that the algee lives on.Or just put a roof over the pond.

Hope this helps Rob.

If you have any more problems drop me a line no pun intended