Correct Filtration

[Bdun111]

I have a question about the attached picture.
On the left side of picture it shows a pressurized filter with UV, which is supplied water by submersible pump, and returns to same area of pond.
On the right side and not connected to other system is a external pump which is supplied water through a bottom drain and used to supply only the waterfall.
My question is, shouldn't the waterfall water be going through the pressurized system also or is this a normal setup?

 

[Tula]

I don't run my water fall through a filter.

I doubt your pressurized filter could handle that much pressure. Filters are rated for water flow, so that should give you some place , to start investigating

 

[Bdun111]

Ty. I have been asking questions about this koi pond waterfall, for my mom, trying to find out why the water in the bottom main area is always murky. My other post were about bottom drains, rocks lining bottom, etc. For whatever reason, the system doesn't seem to work correctly. She was out of the country when it was finished, eight years ago, and the company sas they gave all design and maintenance paperwork to her husband, which he denies. Thereis a submersible pump in the bottom area which goes through pressurized filter and returns as circulating water. This runs 24/7. The upper five smaller areas may have sludge on bottom of them but the water is crystal clear when waterfall not running. The filter is backwashed and psi is never higher than 3.5

 

[Meyer Jordan]

What are the flow ratings in gph of the two pumps? If you don't know the flow ratings, what are the make and model of the two pumps?

 

[Bdun111]

Ty for the reply. The external pump which is only associated with the waterfall is a Pentair afp-120, which is 120gpm, which equals 7200gph.
The submersible pump, used only for circulating the water through pressurized UV filter, is 3000gph.

 

[Meyer Jordan]

One final question-
What size is the Bottom Drain?

And- what is pipe size for each pump?

 

[Bdun111]

I don't know exactly but I believe it is similar to this. The diameter is probably 8-10" and I am pretty sure plumbing is at least 2". This water only goes through waterfall, when it is turned on and pump with the Pentair.

 

[Bdun111]

Here are pipe pictures

 

[Meyer Jordan]

Let us look closely at what is really happening in your pond.
You have 2 (two) pumps. A 7200 gph external that is tied directly a waterfall and a 3000 gph that is tied directly to a pressure filter. The submersible has no mechanical filtration other than the intake grate on the pump and the external has only the leaf basket. Neither of these will filter out anything except fairly large pieces of organic debris. The debris that the submersible picks up delivers it to the pressure filter after chopping it up to even smaller pieces. This will cause frequent clogging of the pressure filter. The external pump also minces the organic debris but returns it to the pond, in essence just recirculating the suspended solids.
Add to this the fact that because the external pump is tied to a bottom drain and is generating over twice the water velocity of the submersible, more debris is being circulated by the external pump than the submersible. This would explain why clarity is much less when the waterfall is working than when it isn't.
The solution to this problem can be approached by the installation of a skimmer and/or the addition of a settlement chamber. A combination of the 2 (two) would be ideal and immediately correct your clarity problem.

 

[Bdun111]

Thanks again for all the information.
The submersible pump goes through the pressurized uv filter system then back into same level of pond. It is ran 24/7.
The upper levels of the pond have rocks on the bottom also, but these areas look 100% clearer, but the circulating water does go through them.
If the circulation is causing the murky water, I would think that since it runs through the uv filter it would eventually get at least a little clearer?

 

[Meyer Jordan]

If the circulation is causing the murky water, I would think that since it runs through the uv filter it would eventually get at least a little clearer?

A UV filter does not remove inert organic matter from the water column. Only adequate mechanical filtration will accomplish that. UVs are primarily for the suppression of planktonic algae.
Keep in mind that even though the pressure filter may be removing some of these suspended solids, they are constantly being added to the pond through uneaten fish food, fish poop, dead insects, dead algae, dead bacteria, wind blown fines i.e. pollen, dead plant foliage, etc.

 

[Bdun111]

So, basically the pressurized uv filter is a waste, no pun intended? I am attaching a picture of the pressurized filter. From searching, I believe it is a Pondmaster. I found a stock cut-away photo of this filter and it looks like the media inside only comes up around 1/3 of the way. Would it be possible to had batting into this? Probably not.

 

[CometKeith]

Hi. Just curious. Where are the pumps? If they are at the bottom of your pond they are going to keep pulling up waste that has settled on the bottom. I always make sure my pumps are a foot or more above any settlement on the bottom. It's very common to have two pumps. One for the bio-filter and one for a waterfall. Also a third of the way up for filter media is typical. Is there any type of indicator on the pump that shows when it needs cleaning and is there a backwash valve that lets you clean it without opening it? Most good filters have that. Typically you don't want to open a biofilter during the season to clean it because you will be removing the beneficial bacteria that has built up in it.

 

[Bdun111]

Thanks for the reply. The submersible pump, which is used only for circulating the water, is located in the bottom area of pond and is currently in a horizontal position. So, I guess the intake area would be one inch to six inches above the rocks it lays on, which are three to four inches thick. Also, the intake area is pointing towards the waterfall (12-18" away), and about six inches away from side wall.
I haven't thought about this, but will try anything.
The pressurized filter has a psi gauge, which is not supposed to go over 5psi, and I have never seen it get above 4, with it staying around 3. We backwash at least once a week. Strange though, I have maybe seen murky water come out during the backwash longer than a few seconds, maybe once.

 

[Bdun111]

More information. We have a similar submersible pump (attached picture), placed opposite of the return water, in a horizontal position, laying on rocks, with intake facing the waterfall, which is about 2' away. Since it is a 360 degree intake, part of the intake will be at rock level, with highest part about 6" above the bottom. Is this correct?