Pipe almost blocked up

[cju]

My father has a Koi pond with 2 UV lamps, old style rectangle filter boxes (one with the extra large bottle brush style nylon brushes then links to another tank with the 'cut up' vacuum pipes, which I believe is for the growth of good bacteria then a pump which then sends the clean water through 2 UV systems past an electronic unit which has wires coiled round the outlet tube (2 sets of wires) before the pipe goes underground then back up the wall of the pond, along the outside to the return aerator unit.

The problem I have is I think he's not replaced the UV lamps, hence a higher than normal blanket weed and clarity of water. I replaced the UV lamps with new lamps. I thought the pump was losing it's efficiency as the flow rate was poor back into the pond (a trickle). I then took the pump out of the filter tank to see if the base of the pump was clogged up and after opening it up, only found a minor slime, to which I then replaced the unit with a new pump and found the same problem. I took the pipe off the pump and it was pumping out water at a large rate (so no problem there).

I then looked at the clear pipe that goes from the UV lamps to the pond and found that the pipe had a thick film on the inside, which I presume is blocking the water.

What can I use to clean the pipe back to normal to allow the water to flow properly again and how can I measure the flow rate at the pond entry point to calculate how much water is being filtered per hour?

Any help with this issue would be much appreciated.

[Gazza]

Hi,

What is in the pipe is it soft or hard and could you not remove the pipe and clean it out manually or do you mean you have to clean it in place

This could be "stuff" that has built up do to lack of cleaning or even a poor flow rate so if the problem does not get solved it will probably happen again so some more investigation may be required.Could you not just replace the pipe with new and start a fresh

If you have a bucket and know how much is in the bucket you can see how long it takes to fill the bucket and then work out how many gallons/liters you are pumper per hour.

[vippymini]

to clean the pipe internally, run a piace of string through the pipe using water to push it through. the tie a rag onto the string and pull it through the pipe. if you also use an extra length of string on the rag you can pull it back and forth a few times...

hope this helps.

[cju]

Gazza,
Thanks, it's soft alage/pond weed inside the pipe and the pipe would be difficult to replace. The large diameter inlet pipe goes underground together with the narrower outlet pipe underneath the crazy paving. the outlet pipe runs under the edge of the pond to meet up at the other end where it then goes down the wall and meets up with the dirty water inlet pipe under the crazy paving (10-12 feet) then comes out of the ground to the filter tanks and the thinner pipe links up to the UV lamp units. I was wondering whether using a pressure cleaner would help remove the grime then maybe some sort of chemical, caustic soda would work to clear the pipe out then neutalise and re-fit ready for use again.

[cju]

vippymini, Thanks for the advice. I think the pipe is really blocked up as only a trickle came out when the pump was on. I think I'd find it hard to get some string to flow along the pipe (maybe 30 feet plus long).

[vippymini]

next option is to connect a hosepipe to the mains pass it back through the pipework

[Gazza]

Remember what ever you do be careful as the fish will end up in the same water so no chemicals and even if you do get all the "stuff" out there could be all sorts of problems afterwords.

[maxinegrundy]

Hello ...
I wouldnt use chemicals ..your asking for dead fish !
What diameter are the pipes ?
You may be able to use one of the cheap drain rod kits that you can buy for under a tenner .. they are usually quite flexable and should easlity go down a 3 or 4 inch pipe....
One of the tools i use for 1 to 1.5 inch pipes is a radiator brush ..the ones that fit down the fins at the back of the rad .. they have a nice sturdy loop on the end that you can tie rope to ..i usually push the brush in as far as it will go ..(the handle is about 25 inches long) the used a bamboo pole to push it in further ..the pull it back with the rope..works for me
The radiator brushes you can get from betterware ...i think they cost about a fiver.
Please dont use chemicals it can go very very wrong
regards
Max