Pump fed but going deeper... - Page 2

wellsi · 22-02-2012, 05:07 PM

Ok; I can see how that would work. I really do appreciate your thoughts and ideas here.

As I see it, with my reluctance to raise the collar of the pond or to bury the entire Nexus 210; I have the following options:

1: Install 4” gravity fed BD that flows into a side pit / vortex buried to pond level height.
Pros:
- I get a fully functioning gravity fed BD;
- Pump and hoses kept out of pond;
- Vortex becomes a pre-pump and pre-nexus 1st-phase filter, capturing the main sludge before water is pumped along to the Nexus.
- Pump less likely to block up

Cons:
- BD could become blocked (assume this is par for course) and would need back-flushing or similar. Would also require Pump to have float switch to prevent burnout.
- Vortex needed;
- Pit bigger than vortex needed to be dug to allow emptying or
- Vortex will need regular de-sludging with a separate sump pump and hose to field (already got this).
- Separate surface skimmer will need its own small pump (currently attached to the main pump)

Option 2: Install BD but connect with 2” alfagomo tubing directly to pump and onto Nexus. If pump is buried adjacent to but below pond level, it will remain primed with water.
Pros:
- Pump and hoses kept out of pond
- No need to bury an entire Vortex, just the pump
- All waste pumped to Nexus (Nexus set up very easy to clean; no need for desludging of a vortex)

Cons:
- BD can get blocked and would be difficult to clean as connected directly to pump; advice?
- Waste is mashed, producing more fines
- Pump is more like to get blocked (although easier to clean out than if placed at bottom of pond)
- Separate surface skimmer needs its own pump.

3: Just use a retro fit BD to pump
Pros:
- BD Easy to clean if gets blocked (fish out and hose down)
- Surface skimmer can be tee’d off the BD hose so both use same pump

Cons:
- Pump just as likely to block as option 2
- Hoses and pumps are in the pond so bit messier, but could be hidden.

Are these the viable options, and have I captured the pros and cons? If so, I can weigh them up and make my decision…

Looking at these, options 1 & 2 are the most desirable to me. 2 seems slightly more desirable given the lack of vortex desludging, but either looks good…

Any thoughts?

Ian

Koipondconstruction · 22-02-2012, 05:34 PM

I would personally say dig out the area where nexus currently sits, block it out and deck over if ground level. Fit a proper bottom drain and pipework etc while you have the chance. You wont need a massive sump pit, you may even be able to use same pump for skimmer
That way its all done correctly and you wont need to throw more money in the future.
If i can help let me know.

Ned · 22-02-2012, 05:39 PM

Forget option 2. That's how my q/tank was set up. I got fed up having to disconnect the pump every time weed or debris got tangled in the impeller due to having no pre filter before it.

Davej · 22-02-2012, 08:17 PM

Ian

I favour option 1 as simple and cost effective.

I'd be thinking of using a suitable barrel and after connecting it up to the 4" drain burying it to form the settlement chamber.

a 4" BD very rarely blocks and you would have the facility to purge it, connect up via the bottom with an upstand that can have a standpipe for isolating / cleaning.

Dont think you would need a flow switch to prevent the main pump running dry you simply take the feed from the barrel for the pump fed N half way up the buried barrel.

Yes you need a dirty water pump in the bottom of the barrel for cleaning, simply close down the feed to the N, stick in the standpipe and turn on the dirty water pump. Purge the drain if you want to and repeat.

Dave

wellsi · 23-02-2012, 07:11 AM

Sold to the man in a hat......

Now I understand how the BD would work and the clean ing out of it.... I looked through Doghouse's pond build post a month or two ago and didn't fully understand the reasons behind the side barrall; now I do.

My last concern was the potetnial blocking of the 4" BD; especially if the side pit won't be as deep as the depth the bottom drain comes out of the bottom of the pond; in effect I'll have a 'waste trap' under the pond and that was the element that concerned me. However Dave, if you say it rarely blocks and can be easily purged, then that's not too much of a problem.
I guess there will be fairly fast flow carrying the water and rubbish through the bottom drain into the side pit; and most of the rubbish will settle once in the barrel where the flow is slower before it's pumped away to the Nexus...
Advice and thoughts have been well appreciated here gents. Many thanks again guys.
Ian

Doghouse Riley · 23-02-2012, 11:03 AM

As with similar systems to mine, purging is usually effective, no pump can replicate the air pressure on the whole of the surface of the pool, that generates the rate at which the water is forced up the 4" pipe. So you should have no worries.

I have always had a home-made tool for if ever too many leaves get into the bottom drain and the connecting pipe. It's a 1ltr plastic lemonade bottle on the end of a pole. The bottle is of about the same "calibre" as the inside of the standpipe socket. I could use this as a "plunger" to "back-flush" any blockage, but it has never been necessary.

efficiencyman · 24-02-2012, 01:11 PM

Go for option 1 that is basically what I do ( although i`m gravity mostly under decking) with my 30" Vortex before it goes onto my other filters.
That way its a prefilter to my CL2, easypod, and 24" Lacron then upto my Clarity Shower, with the heavies and pooh largely taken out the others then stay cleaner for longer.