I currently have an 8000lt pond. On this pond I have 1 50mm bottom drain, this goes to a .75 speck pump then thru a 3 bag sand filter, from the sand filter into a 15lt and 25lt ultra zap pressure bio filter then thru a 15w UV light and back to the pond.

Now I am planning on a 12000-15000lt extension and am having thoughts on how I want the filtration to be.

These are my options, let me know which seems more suitable.

Current

1 x 50mm bottom drain
1 x .75 speck pump
1 x 3 bag sand filter
1 x 15lt ultra zap
1 x 25lt ultra zap
1 x 15w UV

Option 1

3 x 50mm bottom drain
1 x 1000lt settlement chamber (3 sections, over under, section 1 = 300lt settlement, section 2 = 350lt bio balls, section 3 = 350lt alt bio media)
1 x .75 speck pump
1 x 30w UV light

Option 2

2 x 50mm bottom drains
1 x .75 speck pump
2 x 3 bag sand filter
2 x 25lt ultra zap bio filter
2 x 15w UV light

On option 1, would 3 x 50mm bottom drains have sufficient flow into settlement chambers or would the .75 speck pump run it dry? Reason 3 x 50mm is I already have 1 x 50mm bottom drain in my current pond which is cemented into the floor.

or

option 2 better where I just add another 3 bag sand filter, 25lt ultra zap and 15w UV light and have 2 bottom drains in the entire pond where both join into 1 single line to the pump and then from the pump split it again into 2 where each will go to a seperate sandfilter, 25lt bio filter and 15w uv light and then back to the pond.

Which option would be better to go with and why?

thanks

Option 1 with your current 50mm bottom drain plus one more 110 bottom drain. I would keep the sand filter.

50 mm and 110 mm drains to settlement chamber --> Chamber 2 mechanical filtration chamber --> Chamber 3 biofiltration chamber --> pump --> sandfilter --> 30 watt UV --> Back to pond

Include a skimmer and suck 70/30 from chamber 3 and skimmer.

Yes, was thinking of keeping the sandfilter after the chambers for polishing.

So will 3 x 50mm bottom drains provide enough flow for the .75 speck pump? I'm just worried it's not enough, altho if I think of it 3 x 50 = 150 where 110mm is sufficient. Just wondering if I will get the same flow thru 3 x 50mm than 1 x 110mm would give.

Why do you prefer option 1 to 2 Paul? Direct sucking makes me nervous as I'm sure it puts more strain on the pipes ...or is there another reason?

I have seen that a 50 mm pipe only delivers 3500 liters per hour.
3 x 3500 = 11500. Your .75 will pull at least 18 000.

1 x 110mm pipe equals at least 4 x 50mm pipes.

It is always better to suck clean water. If you suck direclty from your drains, the pump does not last as long, it gets clogged with loss of water flow, it "liquidise" the leaves and debris and therefore cause much more organic matter going right through your filtration system back to the pond, or collects in your sandfilter and biofilter with negative effects. The basket traps only big leaves, and particles always go through and need to be empied on a regular basis.

With a settement chamber, the debris stays intact for easy removal to waste, before it reach your pump and filters, and your pump basket stays fairly clean with no loss of flow.

just that the new section of my pond will be roughly around 4m x 2.5m, just that 3 bottom drains in this section I feel would be a waste and probably look wrong.

Thinking option 2 will be the better way for me to go then based on the flow rate issue I may have.

Paul, what if I do the 2 bottom drains in the new extension + a 50mm Pond skimmer, like the ones for pools (one with the weir etc)

Will this be fine if I have a 50mm pond skimmer flowing towards a settlement chamber with 3 x 50mm bottom drains. Or is a 50mm pond skimmer working on gravity feed not going to work as the 4th pipe flowing into a settlement chamber?

I am doign the pond skimmer irrespective where if what I have asked above does not work then I will have direct sucking on 2 bottom drains plus a 50mm pond skimmer\pool weir section.

thanks

Water follow the path of least resistance. Therefore you do not get a lot of flow from a swimming pool skimmer leading to a settlement chamber. The settlement chamber and level of the pond are basically on the same level at all times.

I also believe that the water flow though your chambers should not be too fast. If you only suck from your third chamber with a 0.75 watt pump, the water flows too fast and suck some debris right through.

Therefore I normally split my suction from the chambers and skimmer, each line with a valve to control the source of water.

I did most ponds I have build on the following basis and found that it works very well.





Photos of one I did this way:

https://koionline.forumotion.com/posts-on-pond-building-f17/quickest-way-to-do-a-pond-t293.htm

Paul, you've just given me an excellent bit of advice.....just see if my thinking here will work.

2 x 50mm bottom drains flowing towards settlement chamber
1 x skimmer box 50mm connected to pump

then basically have a 50mm pipe from settlement chamber 3 to pump which the 50mm skimmer will be connected to as well. Then on the skimmer and settlment chamber pipes I will have a ball valve to control the flow from settlement to pump and skimmer to pump so that my settlement does not run dry. I can suck less from chamber 3 and more from the skimmer then.

Therefore then I have a slower more desirable flow thru my settlement chambers as you mentioned is better and a slightly stronger suction from my skimmer which will never leave my pump running dry??

Only problem is what if my backwash goes beyond the skimmer level?

Am i on the right track here or have I completely missed the boat now

That is exactly what I had on the pond mentioned above.

0.75 pump, sucking from skimmer and chambers fed by two bottom drains.



With a pool skimmer, you have at least 20 cm to play with and I never had a problem that it goes below the skimmer during backwash.

excellent, went and read up on the link after I posted....thanks Paul, that has really solved all my problems.

I'm actually on the net now looking for a fibreglass pool, if I find one I will rather leave my current pond as is, fibreglass 2 bottom grains into it and put it next to my entertainment area rather.

Then I have a decent QT facility and a bigger pond.

Funny, my wife an I were lookign into moving to cpt around a year ago and I recognise this place as one of the places I was looking at on one of the property websites....or was it Junkmail...dunno, anyway thats a nce and quick and efficient setup....like it

thanks again, confident with this solution now