Pond filtration upgrade... options options... what to do...

[kindai]

Hey all!

So 20 odd years ago the pond started out with a very common vortex, multibay, pump, UV setup.

Which did the job, but cleaning was always messy and took ages. The underside of the chambers was never truly clean and really it was always a battle for water quality.

Then, as time moved on we upgraded to a cetus > pump > beadfilter > UV setup. (eventually we replaced beads with k1 micro).

The aim was to make cleaning easier, more effective and improve biological capacity.

All of these aims were met, and the k1 micro upgrade was just amazing, however, the mighty sequence 18000 pump is a huge electricity draw, and with plenty of new tech on the market why not use the opportunity to not just switch the pump out, but improve the whole system.


So, after seeing a blue eco RDF in person and being extremely impressed by its design, I ended up buying one.

Rather foolishly, I purchased it on the premise of "we will make it fit" rather than "will it fit?" The blue lines represent the space to work with


So, over to the forum, what would be your "perfect" filter setup following a drum?

I was considering

Drum > A large moving bed bio chamber with k1 micro and the new k3 ultra thats coming out > 2 pumps out

pump 1 going via uv > ozone mixer/protein skimmer if I can find a large one second hand at not extortionate prices > back to pond
pump 2 going via uv > shower > back to pond


Open to other suggestions, what would you do?

 

[NickK]

Perfect or have space for?

I inherited the pond + koi.. that was overstocked with a bear 4500 canister and 2500 pump on a 4500l pond.. I upgraded it to a 9000 canister + 6000l pump and all is well.. except the fish have grown. The pond has a veggie filter at the top of the waterfall that I have already replaced the liner and deepened. So we are planning a new pond (well this has become 'redesign the garden').

Minimal power and maintenance is really my focus.

If I had the space it would probably be;
* Drum mechanical
* Two bio air driven rolling bed K1 media chambers
* UV
* Veggie pool
* Waterfall back to the pond

I think what will be designed will be a 7500l pond with a Nexus 220, UV and a veggie/wildlife pool that feeds into the pond to trap fines using the roots. An enhancement would be to add a Draco drum filter to replace the nexus stage 1 (although I can't with a Nexus 220 but can with a 320 grrr).

Another alternative is to simply do away with the Nexus and go for a drum + bio combo; http://www.dracodrum.com/dimensions.html with 7500l being 2000 US gallons (or 1600 UK gallons) that would mean the smaller drum, for example:

Solum 16 & Standard bio RRP £1,529.17 (excluding local sales tax)
Capable of filtering ponds up to 3000 gallons (58 micron screen)
Or filtering ponds up to 4500 gallons (77 micron screen)

Solum 16 & Large bio £1879.17 (excluding local sales tax)
Capable of filtering ponds upto 4500 gallons (58micron screen)
Or filtering ponds up to 6000 gallons (77 micron screen)

Given the Nexus 220 is about £1000 by itself.. this is more expensive but would cope better (and probably better for fines) with a 58 micron screen.

My only concern is that the pond will have plants, thus it will get muck/grit so I was thinking that a simple vortex would take that out from the bottom drain.

Just thinking a little more.. one of the issues with drum filters is the bio build up and the better drums have a UV light on the inside for this reason. I believe the Draco drums are plastic based so my concern is (a) there's no UV and (b) adding a UV would result in degradation of the plastics themselves.

Hmm.. I have questions that need answering...

Although the mrs has just said - how about we put a budget on the new pond.. £3,000 was her suggestion. So that's the pond build and filtration. Hmm it may go over

 

[kindai]

Just thinking a little more.. one of the issues with drum filters is the bio build up and the better drums have a UV light on the inside for this reason. I believe the Draco drums are plastic based so my concern is (a) there's no UV and (b) adding a UV would result in degradation of the plastics themselves.

Yep, this drum has a UV inside of it.

It's the ultrafines that are what im trying to work out how best to remove, a pressure filter is usually the best, but I dont want to be back to running a pressure filter as that just defeats the purpose.

 

[NickK]

Yep, this drum has a UV inside of it.

It's the ultrafines that are what im trying to work out how best to remove, a pressure filter is usually the best, but I dont want to be back to running a pressure filter as that just defeats the purpose.

It did occur to me that a UV could be controlled by the power to the motor - the 12V line switching a high power line relay for an additional UV bulb in the drum so it powers on only when the drum cleans and reduce the UV impact on plastic further (although the Draco uses less UV sensitive materials).

Once side effect of a 58 micron with build up is over time the holes becomes about 30 micron.. so you end up cleaning the ultra fines. A guy that had this with his Draco also used some jam mat for polishing at the end of the bays, the result was there was still some but less than with the 58 micron. In the end if you want ultra performance then you really want to have a second drum with really fine holes and a UV.

The issue I have is that my 9000 canister even with sponge cubes doesn't remove fines.. actually make that almost-mediums either.. one thing the smaller canister had was a really fine sponge and that really polished the water (but needed daily cleaning).

I'd run a variable flow pump too - that way I can run as needed by the time of year. I also want the option to recycle water back to the pond so I can slow/blend the rate through the filtration if desired.

I think I can work with a Draco price for the budget for the new pond. I'd build the filter area large enough to take a evolve to safe guard future filter options

 

[kindai]

It did occur to me that a UV could be controlled by the power to the motor - the 12V line switching a high power line relay for an additional UV bulb in the drum so it powers on only when the drum cleans and reduce the UV impact on plastic further (although the Draco uses less UV sensitive materials).

This drum doesnt use a motor and control unit

 

[NickK]

Could use a water based gear to rotate the drum during the cleaning cycle..

The only thing with a lower than water drain is that you could result in dropping water level.

Interesting kit will have to have a read of some reviews.

Seems the original company closed.. however an existing company bought the designs/rights so they are still available: https://tolwatertechniek.nl/en/winkel/drum-filter-s/purusaqua-drum-filter/ although they're quoting €3-4000 so above my budget.

One point I do like is the use if the UV light in the filter replacing the need for a UVC (a good point if all your water goes through the filter).

 

[kindai]

Could use a water based gear to rotate the drum during the cleaning cycle..

Thats how it works, has a water piston on the underside which rotates it.

 

[kindai]

Stage 1, saw through all the solvent weld pipework, reconnect with flex hose and move the bead filter out of the way....

 

[NickK]

Just been watching this guy:

Builds his own RDFs and sieve filters!

Very tempted to build my own - washing machine seal, 2inch stainless steel mesh, then order a blanket of 50 micron mesh and simply jubilee clip it on.. the body is plastic welded..

 

[kindai]

Next job, take the cetus out. What a great bit of kit, will be sad to see it go! Worked flawlessly for so many years, part of me wonders if I will regret changing this out.

With that out the way can put the first return UV in place more easily accessible for changing the bulbs out. Also above the water level so no need for bulky valves as it will just drain out once the pump is turned off.

Chopped out the old returns, reconnected with rubber connectors. The pump here is just a skimmer pump. I was thinking about trying to connect it upto the drum and remove the basket, but the work involved to enlarge it to 2 or 3 inch would be simply too much.

New inlet pipework lined up ready to move the drum filter in tomorrow.

 

[NickK]

Looking good

 

[NickK]

On the protein skimmer you can make one out of plumbing pipes then main thing is the air supply.

If you make the height adjustable of the main pipe then you can tune it.

Wrighty has made one in his YouTube videos.

I found that a surface slimmer collected a lot of protein too.

also you may want a bypass in the UV so it doesn’t bottleneck the output.

 

[kindai]

Drum in!!!

Fitting the in-drum UV bulb.

4 inch pipework connected.

Waste pipework connected down to sewage.

Progress so far! Fitment is very tight as you can see from having to saw out part of the wall, but ready to fit the cleaning pipework tomorrow.

 

[NickK]

Looking good

 

[kindai]

Booster pump plumbed in.

Old pump attached to the other side.

And we are filtering!

Its remarkable how quickly this clears a pond, it was very much pea soup with fines as there has been no filtration on the pond for 2 days, after just 2 hours sucking water through the drum the bottom of the pond was clearly visible. I have turned it all off in case of any issues overnight but so far everything seems to be working perfectly

 

[NickK]

Nice it does look like a formula one engine

If you play with the wash sensor height then you can control the pressure pushing the muck against the mesh. Too high and it will simply macerate so once the majority of the muck has gone, lower the pressure (increase wash triggering) and you’ll start capturing more fines.

 

[kindai]

So after a few weeks running, despite all the good of this drum it has a pretty annoying flaw and thats the pop up waste valve.

In theory its great, in reality it simply doesnt work on a pond as the slightest twig, leaf or even some string algae stop it sealing up and thus empties a few hundred gallons out your pond.

Fortunately the fix is easy, raise the drum up and remove the flap. Pipework disconnected (thank god for rubber connectors!!!)

Raised up 5cm.

Pipework re-plumbed.

 

[NickK]

Do you need the pop up in the waste vent? It seems that is the waste chute anyway?

It sounds like what they're doing is collecting the wash waste water then venting in one go - the output then has more momentum. Still not convinced by the non-sloping shape of the waste collector as it will leave waste collected. I have a couple of issues with the Draco - I solved the solenoid leak (needed a teflon washer) and to top it off the new pond is going to be larger than originally planned.. so I may have to upgrade the drum at some point

 

[kindai]

Do you need the pop up in the waste vent? It seems that is the waste chute anyway?

It sounds like what they're doing is collecting the wash waste water then venting in one go - the output then has more momentum. Still not convinced by the non-sloping shape of the waste collector as it will leave waste collected. I have a couple of issues with the Draco - I solved the solenoid leak (needed a teflon washer) and to top it off the new pond is going to be larger than originally planned.. so I may have to upgrade the drum at some point

Effectively yes, the pop up is supposed to allow for a big rush and big purge of water that just drags everything with it. Previously it was underwater, now I have just removed the vent and the collection tray is above the water level. Havent checked it in a couple of weeks so will see later today is theres any waste getting stuck.

 

[kindai]

Do you need the pop up in the waste vent? It seems that is the waste chute anyway?

It sounds like what they're doing is collecting the wash waste water then venting in one go - the output then has more momentum. Still not convinced by the non-sloping shape of the waste collector as it will leave waste collected. I have a couple of issues with the Draco - I solved the solenoid leak (needed a teflon washer) and to top it off the new pond is going to be larger than originally planned.. so I may have to upgrade the drum at some point

Opened it up today. Cant complain.