I'm going to update my pond and wondered if someone could help.

I've currently got a 4 bay filter but it takes up a lot of room and is a pain to clean. The new pond will be c5000lt with 10 or so koi and carp up to 2lb. I want to install a base drain for easy maintenance and was looking at a pressurised filter as I could sink this under my decking. Has anyone got any feedback on these or alternative suggestions.

I enjoy the pond but I'm not a dedicated koi keeper so looking for a good solution on a sensible budget

In reply to Post #1
5k l is way to small for what fish you plan to have.

In reply to Post #2
The same fish have been in a 4000lt pond for the last 5 years and grown from a couple of inches

In reply to Post #3
Not gonna argue here... there is a general consensus for how many certain fish should be per l of pond for the fish and pond welfare/functionality (all that can be up/down due to filtration system etc) and it there for a reason... just calculate biomass of your fish at 2inches and 2lb (and 4lb next year)... good luck with everything.

In reply to Post #4
No worries mate, didn't mean to come across as argumentative, appreciate any guidance. What size would the pond need to be to support a stock of that number

In reply to Post #2
Agreed. Given the right conditions koi will easily reach double figures so it would be better to only have a few in that size pond unless you don't feed them and keep them small.
Most efficient pressurised filters I've had over the years was a couple of bioforce 9000 with UVs . Ideally need cleaning every few days but very effective. I've also got a fishmate back flush pressurised filter with built in uv but it's very poor in comparison. Also a 36 W stand alone UV
Ive brushes in my pump chamber but also good filtration comes via a second pond complete with pebbles, plants etc which requires very little maintenance and returns the water via a waterfall so if you have room I would recommend that.
Plants work well if you can get them established before the koi get too big.

In reply to Post #5
A lot, plenty of that info on web for easy google search, you have to decide what you want and how much you want to invest in filtration etc... some breed 40s in ridiculous small ponds, but in general if you want a nice, clean, healthy environment that will be easy to maintain with min filtration/aeriation and will be home to all sorts of garden life you will have to either make it much bigger or cut down number of fish. Fish will be much happier, healthier less stressed and water quality will be much easier to maintain.

In reply to Post #7
Cheers guys thanks for the feedback, want to get it right.

Was the bioforce 9000 filter the hozelock one? And what size pond was that running?

Can a pressure filter be run with a base drain or is that not possible?

In reply to Post #1
I would stay away from pressure filters for koi. For smaller ponds have a look at the Evolution Aqua Eazy Pod or a Nexus for larger ponds, they're really simple to maintain. They are quite expensive but don't be afraid to get a second hand one.

Also I'd have a look on some of the pond builds on koiforum.uk. You will also get some good advice on there.

In reply to Post #8
Fairly sure they were Hoselock. I had two on a pond about 10000 Ltrs. Many years ago and they look a bit different now, possibly improved.
My bioforce filters contain three stages of sponges which required regular cleaning so would not be suitable for a bottom drain as they stand. Water comes in the top of them and is forced through the filter medium. I suppose you could use a different medium such as alfagrog but not sure how well that would work. You might not have enough volume for effective mechanical filtration. Expensive filter housing if it doesn't do what you want.

If you can find an off the shelf back flushable system that works then I would say that might be worth a look. Depends on space, convenience etc.

In reply to Post #1
go on youtube and watch Quality Nishikigoi channel

aqua nexus systems are what im going to be running once i start and finish the build.

Loads of great info re filters etc on there

In reply to Post #11
Honestly don't see the appeal of nexus'

I've got the 320, it just doesn't keep all the fines out and clear enough for the value of it. I ended up putting a Draco drop in drum in it and it improved the water clarity 5 fold.

By the time you've added this and bought all the nexus it's not cheap.

If I could turn back time I'd just buy a drum filter combi unit or a standalone drum filter connected up to a moving bed filter. Better water clarity and pretty much no maintenance

In reply to Post #12
I think it all comes down to budget in the end. If you've got the money then you could go for a drum and bakki shower but it's probably overkill for the op. I have ended up putting a shower after my eazy pod but it did cope while my koi were still smallish.

In reply to Post #13
They all seem to get mixed reviews, I liked the idea of the pressure systems as they are easy to hide. If I have to have it above ground I could probably stick with my 4 bay

In reply to Post #14
What is your budget mate?

In reply to Post #15
Haven't really got a budget as such but I suppose £250 max for the filter, I've got a brand new pump anyway running my 4 bay. Idea was to save some space and get rid of the unsightly 4 bay box

In reply to Post #16
Then I'd say you need to go secondhand eazypod for that budget

Look on eBay

To mirror other responses here - I'd avoid a pressure filter. Would be more inclined to go for a second hand multi-bay rated for a much bigger pond, gives you freedom to use a range of flow rates and media. Otherwise a nexus range as mentioned.

In reply to Post #18
Cheers all I think I'll stick with my multi bay and spend the money on boxing it in nicely

In reply to Post #11
Hi Joss
I looked at the aqua nexus, but ended up building my own block built filters.
I had used large vortex systems previously but was disappointed.

The block built were great, a large settlement chamber followed by brushes, then fluidised K1 and finally jap matting.
The water quality was superb and it was easy to maintain.

I would always recommend a large settlement chamber before the biological filters, whatever system you use

Pond was circa 4000 gallons

In reply to Post #6
I had a large pressurised filter on my 5000l pond, it struggled to keep the pond clean with only 3-4 small carp.

Changed that for a 4 chamber cloverleaf but that was a pain to keep clean and I couldn't ever get enough flow through it.

Changed to an easypod last year, much easier to maintain weekly. Water tests are spot on even with 5 growing carp. Only thing is it could do with a pre-sieve but I don't have space I have an idea though just don't tell the wife

In reply to Post #20
That's the exact combination of media/order I would use.

I ran a multibay with brushes, aerated and normal jap mat previously. Worked well and would still in place but upgrade to a drum and airated k1/helix-13.

In reply to Post #22
The fluidised K1 is brilliant for biological filtration but the real winner is the settlement chamber.
The more suspended mater you can remove from the water before it gets to the filters the better.

Biological filters which are the most important but are impeded by suspended crap and weed etc, and a nightmare to keep clean.
My settlement chamber was so effective no crap or weed ever reached the K1 chamber or matting and hence they never needed cleaning, other than the light mulm caused by dying bacteria, but that was so fine it flushed through.

The system was designed by Richard at Richdon koi, he's a very knowledgable guy and very willing to help.

In reply to Post #12
sorry for late reply mate.

certainly food for thought

In reply to Post #24
Maybe an easy pod and the unit you already have with jap matt
I've used a nexus in the early days but the biological isn't very reliable , the easy part
In the centre works well enough and is reasonably easy to clean
Depends on how much you want to spend etc
Currently use a drum myself , although they aren't as good as believed
either

In reply to Post #25
bit of a mine field isnt it?

i kept koi some years ago

i had two filters, one was mid water feed, the other bottom drain feed. both chamber filters, one filter water used to get sent to the house and heated through a heat exchanger, the other standard.

both were chambers, up and down flow, with various media, worked fine, but as that was some yrs ago now and im looking into building a new one of 12,000 gallons, ive started to spend most evenings watching bloody youtube films on filtration

In reply to Post #26
The way to go is a drum filter with an added bio chambers if you want high water quality with smaller amounts of daily maintenance on a smaller footprint, evolution aqua filter are very good to though Joss but huge old units, Quality Nishi koi loves them like you say! I've watched a number of mates go through various upgrades and they all seemed to end up on a drum for superior mechanical solids removal with a bio chamber or two for the nitrification side of things.

In reply to Post #1
Initial stage - drum, or a sieve as a cheaper alternative.

Bio stage - bio chambers or showers.


Nexus/Easy pod aren't bad but you always have problems with fines and end up adding other stuff and modifying them.

Pressure filters are utterly useless unless you fancy cleaning them out every single day, even then they're poor as bio filtration.

Multi bays are outdated and a pain to clean properly, very often there's a massive amount of thick sludge sitting in the bottom of them and within the media. They can be modified with some work though as bio chambers only, either with K1 or cartridges made from Japanese matting that simply lift out and leave it empty for easy cleaning.

In reply to Post #27
Time for more homework then mate before i start !

Good thread this is, beats talking EU and bait

In reply to Post #28
Easy pods are great to run a skimmer through or smaller ponds with less loading, we use drums in the water industry and it's incredible what they can achieve when abstracting water from a swollen river intake!
My mates fitted a micro switch on his drum that runs on a fine level tolerance and back flushes the drum on reaching a certain head, it even counts how many washes it does and displays it, virtually no maintenance on 5.5k gallon pond. It'll be the way I go when I build my pond, just have buy my forever home first

In reply to Post #30
I'm sure this pond is only 5000 litres so maybe we all better calm down 😂
Id stick a three in bottom drain run to start with as the flow rate doesn't have to be massive
Continue with the multi bay to start with and see how it goes, maybe put a cheap skimmer in and seal it off, just in case you decide to add more stuff later on
Also set it up gravity fed , this would enable you to hide the filter

In reply to Post #31
Everybody's calm buddy, 10 carp that'll only get bigger and further load the whole system, your far better off over filtering this gives a bigger buffer from problems further down the line.

In reply to Post #32
Apologies What I was trying to get across is that it's a small pond and it isn't worth going
too far initially , trying to walk before running
The capped off skimmer would allow an easy pod or whatever to aid further improvements
Should also mention adding a 3 inch outlet on the skimmer
I've built quite a few ponds and maybe have different views to the normal advice that I too adhered to initially
And make mistakes
I won't go into filters as it's like the barbed, barbless hook debate
When I built my first pond I had two 4 inch drains , a nexus , bead filter and shower
What I learnt was that a single biological filter works best
And my 4 “ drains are a pain , as they need purging etc
I now have a single biological filter , with brushes at the front and aerated matting running in line
With the flow and drum and that's it
My skimmer diverts straight back into the pond
Hope this helps👍🏻

In reply to Post #33
Cheers all, I'm going to run with my 4 bay and set it up gravity fed from a base drain. Seems to be the most cost effective all round solution.

Now to get my head round adding a glass window