Hi -

A 2 bag sand filter on a ,75Kw pump is not a good idea. It is too small and will clog very quickly and a lot of fine stuff will blast through the sand bed. You will have to use something else or use another 3 bag sand filter in parallel to this small filter. I am sure there is a lot of pressure being generated in this small unit. This is the main reason why you have to back wash so often. If you get the sizing right with the sand filter or filters your problems will be over.

The quote for R9000 - what was going to be done for this price?

Diagram of suction onto pump from bottom drain and skimmer. Try not to use a normal T into one 50mm pipe. Water is a strange thing and you will get more suction form the straight part than from the section coming in from the side. This is a more balance and effective way to increase flow rates.

Ok - so how do I load an image? Not sure what is going on here ....

Chris

1 x Speck 3 Bag Sand Filter R2 690.00

3 x Bags Sand R225.00

1 x 25 Liter Bio Filter R850.00

1 x 25 Liter Bio balls R600.00

1 x Pre Filter R975.00

2 x 50mm Venturi R290.00

Pipe, Fittings, ball valves, consumables, etc R1 940.50

Installation R1 424.50

The more i look into this the more i find that my equipment is inadequate.

The pump which i thaught was a 0.75kw is actually a 0.45kw pump. Porpoise 90/10

What size pump should i be running? do you get low energy pumps?

Do not despair...two smaller pumps is better than one big one...in case one packs up U have back up.
Yes there are low energy pumps like PC18000, and the ecotouch, which U can run on low for normal operations and put on high for backwashing.

Hi -

Put the brakes on please.

A Speck Porpoise 10 will give you about 15,000L per hour if there are no restrictions. You have a 25,000L pond. So your pump capacity is fine for your pond volume. And you are only using about ,45Kw per hour. Don't spend more on another pump.

You just need to eliminate the frictional losses and restrictions as much as you can.

The low energy pumps are fine but they cannot create much pressure - so they can only lift water up 50cm or so. They cannot push the water through a pressurized system as you have. Therefore to use a low energy pump you will spend much more money converting your system into a gravity fed system. The immediate problem you have is the 50mm bottom drain. You cannot feed enough water to a low energy / high volume pump through 50mm.

I suggest the pump is great for your pond. In the last 20 years pond builders have done a great dis-service to koi keepers - they have build poorly designed filtration systems and then simply put 1.1kW pumps on them to overcome the restrictions. A sort of brute force and ignorance approach. But in today's world a 1,1Kw pump will use about R1000.00 per month on electricity. The ,45Kw Speck will use less than half of that and still work well.

There are variable speed pumps on the market which can vary the speed and volume of the pump between ,3kW - ,5kW and ,75kW. Excellent pumps and well worth thinking about as you can run on the lowest setting and volume through the winter and for some hours during the day in summer saving thousands of rands..

With a waterfall you can eliminate the venturies. Another sand filter (new or second hand) would help. Then a second biofilter - or you can make your own. UV's become not necessary after a few years as your pond matures.

Use the piping - suction > pump > sand filter (sand filters) > biofilters or biotubes > back to pond. Don't split the returns between the UV and the biofilter.

So - the heart of the system the pump is fine.

Chris

Summary

1) Keep the pump as is.

2) Replace 2 bag filter with 3 bag filter

3) use 45 degree bends and no 90's

4) shortest distance from pond back to pond

5) Suction from Bottom Drain > pump 0.45kw > sand filter (new 3 bag) > sand filter (existing 2 bag) > UV here? > Biofilters or biotubes > or UV Here? > Baki Filter > back to pond over waterfall ?


Hope this is correct ???

As you are using a ,45kW pump the 50mm bottom drain is not the end of the world. Pumps are generally better at pushing than sucking. Try to get the pump on ground level and not above the level of the water. Any height up to the pumps and the output falls dramatically. Have the pump fairly close to the pond if possible. The filters etc can be further away because of the pushing power of the pump.

Try to conceal these things to make the area look good in the garden.

Pump > 2 sand filters in parallel (not sequence i.e. one ofter the other){most important - I have diagrams for you} > then if you are going to make bakki shower or buy a bakki shower you do not need any bio tubes or bio balls etc. The bakki shower is your biofilter and is much more efficient than the bio-tubes.

The sand filters in parallel are your mechanical filters and the bakki shower the biofilter. That's all you need.

Send me some pics of your set up and surrounding area directly to me and I will look at the placement for you. I don't always look at the forums and you will get a quicker reply this way.

neaves@mweb.co.za

Hope this helps.
Chris

I emailed you the pics.

Please send me the diagrams.