Should i downgrade my Oase filter system?

[Marcus_1234]

Hello All,
we bought a house a few years back and the previous owner was an avid Koi fan.
He constructed a pond with a volume of 45m (around 12,000 gallons), at it´s deepest, about 8 feet, the lowest 4 feet.
Basically on the far side of the bridge is the deepest point and in front of the bridge the shallowest area.
To maintain the pond the previous owner installed an Oase Proficlear Premium system with 1 x 20,000 litre and 1 x 10,000 litre pump.
I´ve attached some photos of the pond, filter system and water pit where the pumps sit.
At the time there was 25 large koi living in it but he took them with him.
So, after we moved in we put in 2 small koi (about 25cm now) and 12 x Orfe (about 15cm).
I have no plans to introduce any more fish.
I feel that, for the fish we have, the current system is overkill and takes up alot of the garage space.
I´d like to replace it with a smaller system, an Oase Screenmatic 90000 and have it sit outside next to the water pit instead.

BioTec ScreenMatic² Set 90000

Flow-through filters

www.oase.com

Some more information.
I live in Berlin, Germany where the temperate during winter can go down to minus 10 degrees (14 Fahrenheit).
For some of the winter time (maybe a month) the pond freezes over except for where a small waterfall is.
The pond has a few sea rose plants in it.
The pond has 3 water return pipes (that take the water back to the water pit), one at the base of the deep pond, one in the shallow pond and one as a skimmer which collects surface residue/waste. Each return pipe has a valve allowing each to be closed individually (located in water pit).
Currently the UV is switched off as it´s a nightmare, the way the system was installed (against the wall), to attempt to open and replace the bulb!

My questions are;
1. Does it make good sense to change the filter system over and is this the right filter choice for what i have?
2. Should these filter systems be turned off and drained over winter once the water temp falls below say 54 fahrenheit or should i leave them running (on low)?
3. If the filter systems are turned off, should the pond be aerated in the shallow area or will the pond hold sufficient oxygen during Winter?
4. If an aerator is not required, should i at least maintain a hole in the ice when frozen over?

Thanks for taking the time to read through all of this. I really appreciate any advice or further suggestions.
Marcus

 

[j.w]

and welcome @Marcus_1234
Think I missed your first post way back when. Nice setup and lots here use bogs to filter their ponds as they seem to work so well

 

[Marcus_1234]

View attachment 154395and welcome @Marcus_1234
Think I missed your first post way back when. Nice setup and lots here use bogs to filter their ponds as they seem to work so well

Thanks @j.w , a bog filter looks interesting but i don´t want to make this pond any bigger than it is

 

[WaterGardener]

I'm a firm believer that you can't have too much filtration. So I wouldn't downgrade it.

 

[fishlips]

Also no downgrade but upgrade to a bog inside the existing pond. With a little rework that pond will not get bigger and you may get a waterfall.

 

[GBBUDD]

beautiful set up .
and yes it looks like there were serious are any of the rotating drum filters ?

My questions are;
1. Does it make good sense to change the filter system over and is this the right filter choice for what i have?
2. Should these filter systems be turned off and drained over winter once the water temp falls below say 54 fahrenheit or should i leave them running (on low)?
3. If the filter systems are turned off, should the pond be aerated in the shallow area or will the pond hold sufficient oxygen during Winter?
4. If an aerator is not required, should i at least maintain a hole in the ice when frozen over?

looking at your water clarity , you could stand to step up the filter. you may have only a few fish now but if you are a good Stewart and give the fish a descent home your population will double every three years or less.

if your pond has the possibility of icing up and over flowing the on the coldest of the winter shutting down may be required. yes a opening probably two in your case one at each end may be needed

 

[Marcus_1234]

beautiful set up .
and yes it looks like there were serious are any of the rotating drum filters ?


looking at your water clarity , you could stand to step up the filter. you may have only a few fish now but if you are a good Stewart and give the fish a descent home your population will double every three years or less.

if your pond has the possibility of icing up and over flowing the on the coldest of the winter shutting down may be required. yes a opening probably two in your case one at each end may be needed

Hi @GBBUDD , yes the system has a rotating drum filter (at back of photo). The filter can be ramped up and down but it does not seem to make much difference to water clarity (although there has been times when it is crystal clear). I put it down to maybe the UV bulb needing replacing and the koi disturbing the existing sediment (which i remove each season)???

 

[cas]

Very pretty pond!