Hi Scruffy,
Sorry for the late reply.
I have been looking at this a couple of times but there's quite a lot to take in, looks very good as far as I can tell. You seem to have taken everything into account here.
I'll give my thoughts on what you posted:
scruffy.thedog wrote: 21 May 2021, 19:10
So at last I have the resources to remove my pump fed pond to an air lift pond ..build will start as soon as the house extension is finished > autumn 2021 The kidney shaped natural low level pond will be about 32 m3.
2 bottom drains 16m3
That's reasonable. 8000l\hr per drain.
2 skimmers ? 4m3 each = 8m3
Sounds good too.
= max 24 m3 going through max going to a 35m3 drum filter
https://burtonsaquatics.com/burtons-bd- ... ilter.html
From the drum filter flow of water to x2 20m3 capacity K1 beds
https://burtonsaquatics.com/new-bio-chamber.html
I am no expert on the filtering capacity of K1 media but overspeccing a little is always a good idea.
3x Airlifts will be SLL20--110-145cm—20m3 -12 watt-0,6 watt
Ideally you could reach this flow rate, even in less than perfect conditions with 10000 to 15000l/hr you still have 30 to 45000 liters of flow which is around what your filter would allow.
This is over engineered capacity but having had several ponds in the past its all way better to have a more wriggle room and capacity that you expect the system to need
Completely agree, you can always decide to run less pumps and close part of the filter later if needed.
I have built in the design in some returns to the pond that allow me to return some water back to the pond unfiltered if I want to
Comments about the design location of returns skimmers etc will be welcome at this early stage…?
To be honest I don't see any problems with your design, I encourage other readers to correct me if I missed anything though.
is it too over capacity ….do I only need 1 K1 media box as max flow is going to be about 24m3 as this does not take into account resistance of pipes etc…..( having more media means less stress on the system)
As I said before, I think the cost of building this system with overcapacity is worth it compared to the problems you could run into if you build exactly to minimal filter requirements. I'm pretty sure you could also run this pond with one airlift, but that would be risky and your water clarity would probably be worse. In terms of biological filtering capacity, I am not experienced with K1 so I would advise you to read up on the manufacturers specifications and try to read up on other people's experiences with this media
do I really need the over flow capacity shown in green pipes for unfiltered water to return to the pond via the drum filters without being filtered?
I would advise to build these overflows just in case. Theoretically these should not be needed as you're not pumping water to your drum, the airlifts are pulling water through, which would sooner cause the water level to be too low in your drum chamber. I will ask Marc to see what he thinks about this.
would this set up create to much turbulence in the water for the koi are there enough quite spots for them to be ( the pond will be 2m deep)?
thanks for your input
scruffy.thedog
At that depth I would be very surprised if there would be problems.
A couple of things to keep in mind:
- Make sure your drains do not have any sharp corners (90 degrees) as this will hurt flow. The same goes for the filter, if possible avoid using 90 degrees elbows and try using two 45 degrees elbows instead.
- If your airlift and drains are 110mm, make sure your filter transits are at least 110mm as well. Alternatively, calculate the surface area of the 110mm pipe and match or (preferably) exceed this in the filter to avoid bottlenecks.
For example:
a 110mm circle has a 9503cm2 surface area. If you want to use 60mm transits, you would need:
Area = Pi times radius squared = 2827cm2
9503/2827 = 3,36
Which means you would need four 60mm transits to match the maximum flow of one 110mm transit.
Do keep this in mind as airlifts absolutely require these pipe diameters to allow for good flow. Pulling through smaller diameter piping will hurt your flow tremendously.
