Please help guys. I have a 25000 l pond. I use a .75 kw "poolpump", 4 bag Badu
sandfilter, a 55l Bio filter and a 55w Uv light. I also use a pre filter from the pond
before this system. Somehow my water in the pond is not 100% clear. I was then told not to use Clinofilter as it is too rough. I am still new to the whole thing and any advice would be appreciated. Will look at a bubble bead filter at some stage. Thanks

Hi Charl

What is your maintenance routine like?

How often do you backwash and clean the filters?
How many bends do you have in your piping?
Do you know how often you are turning over your water?
When last did you change your UV globe?
How many fish in your pond, sizes?

Think these Q's are a good place to start for now.

Perhaps a few pics of your filtration setup, would like to see size of piping, bends etc...you may have as well

Thanks for your response. We backwash the filters once a week (through the manhole) stirring the clinofish stone as well. I will check how many bends etc. Have a photo somewhere. Must check how to post a photo. Sorry for being so dof but never thought of the turnover time.
We have the uv light since November last year and still using the same tube. We did have a low flow (low pressure) system at one stage. Could have affected the the tube. We have 17 koi. 3 x 150mm, 5 x 250mm, 6 x 450mm and 3 x 500 Plus. (app sizes).
The pre filter (with a 800mm brush) picks up a lot of algae.

Will try to do the photo thing asap.
Regards
Charl

charl my setup is die selle maar ek het nog `n 3 sak filter om te polish entwee 5 uv`s op ek het ook geen probleem gehad nie tot my uv`s begin ingee het ek moet hulle nou vervang my water is kristal helder ek backwash ook elke derde dag en een keer `n maand met air assist

Is yur water green or is it murky but not really green?
Many people use Zeolite in their sand filter and it works well.

Dankie Vossie
Ek is gese my pomp sal nie deur twee filters kan pomp nie. Hoe het jy air opgekonnekteer? Dink dit sal nogal help. Die Clinofish is nogal swaar.

Neli
The water actually fairly clear but one can see some particles - almost like algae in the water.(probably is algae). It causes the water to be not as clear i would like it or should be.
I was told the clinofish is not catching the finer stuff and should replace it with glass type resin.

ek hardloop met qulity pompe .75 en hy druk hom gemaklik deur die koisand my valves sit bo op die tanks vas ek het `n ou pomp gesny om op die waste pyp te pas want hy gooi baie sand uit soos hy blaas

Charl Jacobs wrote:

Neli
The water actually fairly clear but one can see some particles - almost like algae in the water.(probably is algae). It causes the water to be not as clear i would like it or should be.
I was told the clinofish is not catching the finer stuff and should replace it with glass type resin.

I dont think that is true...Clino fish=zeolite, Chris Neaves uses it in his sand filter and his water very clean...Might be just algae or combined with something else...Do U rinse your pipes after back washing?
If the zeolite is not removing all the particles...your bio will be dirty...is it dirty?

Photos of Charl's setup posted on his behalf:

Are those pebbles inside your pond?

Hi Neli
No not sure what that reflection is. We vacuum our pond frequently. There is only volcano pebbles in two plant boxes (with plants) on the other side of the pond. Grumpy (the wife) will check the bio filter this weekend. She was scared to disturb the bio material. Please pardon the corner of the pond. That part is to get a deck (busy on the other side and the bridge). A "divorce case" is looming as we cannot agree on the final layout. Hie hie. Thanks for all the advice.

Charl Jacobs wrote:

Hi Neli
No not sure what that reflection is. We vacuum our pond frequently. There is only volcano pebbles in two plant boxes (with plants) on the other side of the pond. Grumpy (the wife) will check the bio filter this weekend. She was scared to disturb the bio material. Please pardon the corner of the pond. That part is to get a deck (busy on the other side and the bridge). A "divorce case" is looming as we cannot agree on the final layout. Hie hie. Thanks for all the advice.

Darling,
U dont need to vacuum your pond if:
-U put your returns properly in order to create a circular flow in the pond
-Put e perforated pipe on the bottom if U dont have BD....
Remove planter boxes...Plants in pots and koi supposedly dont mix well, and will obstruct your flow.

Hi Charl,

There are a few things going on here.

In order to get a filter to trap solids the size of the media should not be larger than about 5 - 6mm. And the size must be uniform throughout. Anything larger than this and it becomes a biofilter where the water just moves easily through the filter. Clinofish is terrible as a mechanical filter as it is graded from 3mm - 12mm. If you use an even grade of about 5-6mm you will get entrapment of solids and your water will clear. Even the new clino fish - now a uniform size - is too large for mechanical filtration.

An easy remedy is to revert to aquarium gravel of 3 - 5 mm and clean the filter regularly.

Another thing that is definitely happening in your system is the ,75W is very powerful and it is simply pushing the fine solids through the sand filter - 1) because of the pressure and speed of the water 2) because of the large spaces in the Clinofish zeolite.

You can reduce the speed of the water through the single sand filter by adding another sand filter in parallel. Or you can reduce the flow through the filter system by placing a smaller pump on your system. This will save you costs and still work well.

Another solution is to split the water output after the pump. Immediately after the pump split the water - one pipe directly to your biofilter and the other to the sand filter/UV. Make sure you have some circulation inside your pond so that everything gets diluted and mixed up. Place a valve on the outlet to the biofilter as the sand filter will create some back-pressure and more water will want to go directly through the biofilter. You can then control the amount of water going directly to the biofilter.

Do you have a surface skimmer on your pond?

How long has the pond been running?

Chris

Hi everybody. First, thanks for all your help. Chris, we have a skimmer but do not use it 24hrs a day. Maybe we should. It looks like fine algae. Will seriously consider all the options. This system is running for about 5 months. I need to make any changes before the summer hits us.

Hi -

The surface skimmer will pick up the very fine particles that settle on the surface. A surface skimmer will really help you clear the water.

However, in your filter system - a lot of fine material (algae included) just gets blasted through. Fix this and you are away.

Chris

Chris Neaves wrote:

Hi Charl,

There are a few things going on here.

In order to get a filter to trap solids the size of the media should not be larger than about 5 - 6mm. And the size must be uniform throughout. Anything larger than this and it becomes a biofilter where the water just moves easily through the filter. Clinofish is terrible as a mechanical filter as it is graded from 3mm - 12mm. If you use an even grade of about 5-6mm you will get entrapment of solids and your water will clear. Even the new clino fish - now a uniform size - is too large for mechanical filtration.

An easy remedy is to revert to aquarium gravel of 3 - 5 mm and clean the filter regularly.

Another thing that is definitely happening in your system is the ,75W is very powerful and it is simply pushing the fine solids through the sand filter - 1) because of the pressure and speed of the water 2) because of the large spaces in the Clinofish zeolite.

You can reduce the speed of the water through the single sand filter by adding another sand filter in parallel. Or you can reduce the flow through the filter system by placing a smaller pump on your system. This will save you costs and still work well.

Another solution is to split the water output after the pump. Immediately after the pump split the water - one pipe directly to your biofilterIs the bio filter not supposed to get clean water only???Is dirty water not going to affect the type of bacteria growing in it...and disturb the nitrosomas???I mean more heterotrophic bacteria will grow which inhibits the growth of the nitrosomas... and the other to the sand filter/UV. Make sure you have some circulation inside your pond so that everything gets diluted and mixed up. Place a valve on the outlet to the biofilter as the sand filter will create some back-pressure and more water will want to go directly through the biofilter. You can then control the amount of water going directly to the biofilter.

Do you have a surface skimmer on your pond?

How long has the pond been running?

Chris

Hi Chris,
The time I was in your house U told me u have zeolite in the sand filter....Have I misunderstood U?
Is your sand filter not mechanical filtration???

Hi Neli -

Happy 96th birthday.

Yes I have zeolite in my sand filters that work on my surface skimmer. Had gravel for about 25 year then decided to try zeolite. But the important thing is the size it is 5 - 6mm - and not whether it is gravel or zeolite. Place large gravel in a sand filter and you have the same problem. The estimated size differential in the media between a filter acting as a mechanical filter and one that is acting as a biological filler is about 5mm. If you think about it mechanical filters and biofilters are the same design.

There were two points made in the reply - 1) the media had to be of uniform size to work well/efficiently and 2) clino-fish zeolite that you can purchase in bags is too large to be an effective mechanical filtration. When the zeolite is saturated with ammonia it simply becomes a surface area for bacteria to grow on. It has a massive surface area and makes a good biofilter media.

The reason zeolite was used in sand filters was to lower the weight of the bed and therefore make back washing more efficient.

The new clino fish zeolite that was seen at our National Koi Show is much better as it is a uniform size and can be used as a mechanical filter to trap solids. But, in my opinion the size is still too large for really good mechanical filtration.

So any filter becomes a mechanical filter when it traps solids. The name sand filter is misleading because they can be used as mechanical filters or biological filters. Sand filters are nothing more than pressurized tanks that have been adapted for use on koi ponds. Use a large media and the solids are not trapped and it become a biofilter. Use a small media and it will trap solids - it then becomes a mechanical filter.

Yes - it is important to keep the solids and organics away from the biofilter media. In reality this is impossible as no mechanical filter is 100% effective. So some organics and some solids will always get through to the biofilter. This is the reason why you must completely flush your biofilter from time to time. The bacteria in biofilters are really tough and can withstand a good rinse and flush.

In the case we are discussing here - the clino fish is just not trapping anything and the large pump on the one sand filter is simply blasting the organics and solids through the system. There will be a fast turnover rate and it is better to trap a large percentage of the solids in the sand filter than not at all. The solids moving to the biofilter will mostly pass through it and be diluted into the system but these will be filtered out with every pass through the sand filter.

Chris

Chris Neaves wrote:

Hi Neli -

Happy 96th birthday.

Yes I have zeolite in my sand filters that work on my surface skimmer. Had gravel for about 25 year then decided to try zeolite. But the important thing is the size it is 5 - 6mm - and not whether it is gravel or zeolite. Place large gravel in a sand filter and you have the same problem. The estimated size differential in the media between a filter acting as a mechanical filter and one that is acting as a biological filler is about 5mm. If you think about it mechanical filters and biofilters are the same design.

There were two points made in the reply - 1) the media had to be of uniform size to work well/efficiently and 2) clino-fish zeolite that you can purchase in bags is too large to be an effective mechanical filtration. When the zeolite is saturated with ammonia it simply becomes a surface area for bacteria to grow on. It has a massive surface area and makes a good biofilter media.

The reason zeolite was used in sand filters was to lower the weight of the bed and therefore make back washing more efficient.

The new clino fish zeolite that was seen at our National Koi Show is much better as it is a uniform size and can be used as a mechanical filter to trap solids. But, in my opinion the size is still too large for really good mechanical filtration.

So any filter becomes a mechanical filter when it traps solids. The name sand filter is misleading because they can be used as mechanical filters or biological filters. Sand filters are nothing more than pressurized tanks that have been adapted for use on koi ponds. Use a large media and the solids are not trapped and it become a biofilter. Use a small media and it will trap solids - it then becomes a mechanical filter.

Yes - it is important to keep the solids and organics away from the biofilter media. In reality this is impossible as no mechanical filter is 100% effective. So some organics and some solids will always get through to the biofilter. This is the reason why you must completely flush your biofilter from time to time. The bacteria in biofilters are really tough and can withstand a good rinse and flush.

In the case we are discussing here - the clino fish is just not trapping anything and the large pump on the one sand filter is simply blasting the organics and solids through the system. There will be a fast turnover rate and it is better to trap a large percentage of the solids in the sand filter than not at all. The solids moving to the biofilter will mostly pass through it and be diluted into the system but these will be filtered out with every pass through the sand filter.

Chris

Thanks Chris for the Happy birthday...it makes me feel a spring chicken compared to 96...He he he!
I now understood it...for me it was: if it is good enough for Chris it is good enough for me...Good U told me...I was about to change my gravel/sand which I drugged all the way from SA to zeolite...
BTW they sale now very uniformly crushed zeolite...3-4mm they have two sizes..the normal larger chips like...and the smaller uniform size.
BTW I am using 5mm sand in my SF...and it cleans very well, but was hard to wash...so I connected a compressor to it.I am also using 750W spec on one sand filter...works well.