# Filter for dirty lake water



## mrdman (Mar 7, 2021)

Hi everyone!
I have an irrigation system that uses lake water with a measured pressure of around 3.4 bar (50 psi).
I recently replaced the noisy impact sprinklers with MP rotators. It was then that I realised that I had an issue with dirty water. The incoming filter was empty! So within a few days, the little filters in the MP Rotators clog up with mud.

I'm looking for advice on what I should do. I guess the easiest option is finding the mesh / disk element for the filter I have, however, I do wonder why the previous owners removed it. Maybe it clogs up too quickly? It's an Amiad. So unless anyone here is familiar, I'll have to contact Amiad.

Else, I guess I could change the MP rotators to something more forgiving, but then dirty water isn't great on the valves I guess. I've just replaced one, and the others don't look in great condition.

Lastly, replace the filter completely for something more appropriate for my situation. Maybe a self-cleaning one? Or one that is easy to backwash or something? Do they exist at reasonable prices for home owners? What about a sand pool filter even? Could that be a solution?

Any guidance is greatly appreciated!


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## mrdman (Mar 7, 2021)

Just spoke to someone at Amiad, and unfortunately simply fitting the element is a no go. It would clog too quickly. I assumed that. And he doesn't recommend semi-automatic ones either because I don't have the pressure to allow them to clean apparently.

So now my choices I believe are changing out the MP Rotators for something more forgiving and just living with the dirty water or making some sort of filtering system myself. I wonder if a pool sand filter could work... anyone done it / seen it done?


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## burntfire (Dec 10, 2020)

I'm not a well/lake expert so I'll let others chime in.

You may be able to look at the Rain Bird VCS-R10V as a possible option.


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## mrdman (Mar 7, 2021)

burntfire said:


> I'm not a well/lake expert so I'll let others chime in.
> 
> You may be able to look at the Rain Bird VCS-R10V as a possible option.


Many thanks for the tip. That does look. Unfortunately, I can only find a document about it and can't seem to find it sold anywhere. Even on Rain Bird's online store it doesn't appear, so I will get in contact with them now.

Do you happen to know if it works well with mud/slime as well? It's sort of a black muddy slime that I'm seeing on the MP Rotator filters.


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## mrdman (Mar 7, 2021)

I did some measurements before emailing Rain Bird, and my system is:
25 sec to fill 25 litres at 3.2 bar (46.4 PSI)
30 sec to fill 25 litres at 2.4 bar (35 PSI)

Flow rate at 46.4 PSI = 1 l/s = 60 l/m = 3.6 m3[/sup]/h = 15.85 GPM
Flow rate at 35 PSI = 50 l/m = 3 m[sup]3[/sup]/h = 13.2 GPM

Then, Rain Bird got back to me.

_The automatic cleaning filters we sell are for higher flow applications than what you have (typically over 75-100 GPM and over 45 PSI).​_
I did spot this 169euros pool cyclone filter: Datasheet
That says it runs from 3m[sup]3/h which is where my system is at. The only question is would it take out what I need. Do you think it's worth the gamble to try? It wouldn't be a complete waste of money, as I'll be doing a pool filter system soon, so could always use it for that.


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## mrdman (Mar 7, 2021)

Having researched this some more, I've just took a look at the MP rotator filter again, and I think when I said mud, I was mistaken. It's covered in a slimey light brown substance which I assume now is algae rather than mud. So presumably that means cyclone filters are out. Maybe any filter will clog too quickly and I'm better off going back to the old heads I had. Ah what a shame, I loved those MP rotators.


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## g-man (Jun 15, 2017)

Did you check how your lake pipe is mounted? Can it be moved deeper or further out to try to pick less debris?


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## Lust4Lawn (Aug 4, 2020)

I've heard of people even having issues with MP units and hard water. You may need to switch to a rotor unit instead of the MP models to really cure your issues.


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## mrdman (Mar 7, 2021)

@g-man Unfortunately, I don't have any control of the lake side of things. The water comes into the property via a meter in the cabinet on the outside wall.

@Lust4Lawn I just did a search and yes, I see some people have had issues with algae blocking the filters inside them too. I wish I read that before buying them. The one good thing is that the previous sprayers never really seemed to block, so maybe I'll put them back in for now until I decide what to do. They were Rain Bird VANs (no filter screens) most of them. Are they particularly good for dirty water? Or is there something better? (Ideally I don't want impact sprinklers, but will do if I must). Or should I run the MPs without the filter screen maybe?

Another thing that comes to mind now is when I had access to the main pipe runs, inside the pipe was very slimy. Is that normal?


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## bassadict69 (Apr 2, 2018)

The end of the pickup on my lake drawn intake piping has a filter sock on it that I remove and wash several times each summer.


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## mrdman (Mar 7, 2021)

bassadict69 said:


> The end of the pickup on my lake drawn intake piping has a filter sock on it that I remove and wash several times each summer.


How often would you say you have to clean it? Weekly? Monthly?

I'm just debating whether to knock the filtering on the head and go with other more forgiving sprinklers, or continue along the filtering path...


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## bassadict69 (Apr 2, 2018)

I have to swim to get to it so I generally clean it as soon as I can bear the water temp in the spring and again mid summer. I am not real sure it even needs to be cleaned, I have never noticed any performance loss.

https://www.amazon.com/Superior-Pum...ds=water+intake+screen&qid=1615728550&sr=8-17

https://www.amazon.com/gp/product/B000HOT0ZU/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1


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## mrdman (Mar 7, 2021)

Ah ok, I thought you meant the filter on your property. I don't have control of the lake side of things. That's run by the community and pumped into our houses via meters at the properties.

I think I'm going to cancel the plan of filtering, and try and use the dirty water as is and change out the MP rotators for something else. Do you think before switching them out, I should try running the MP rotators without their little filter screens? Could I permanently damage them?


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## g-man (Jun 15, 2017)

Can you talk to the community? See if they can add a filter to take care of the larger items? or maybe it had a filter and it is broken. Then you can a second stage (or even a third), to filter the next level up to the filtration level the mp needs. The mp design manual has the desired filtration information.


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## mrdman (Mar 7, 2021)

g-man said:


> Can you talk to the community? See if they can add a filter to take care of the larger items? or maybe it had a filter and it is broken. Then you can a second stage (or even a third), to filter the next level up to the filtration level the mp needs. The mp design manual has the desired filtration information.


Ideally, I don't want to bother anyone if at all possible. I'm new to the community (about 250 houses) and so don't want to be the Englishman turning up and giving out about their lake system that they all use. That would be a last resort if I can't get a working system. 
I think the major problem for me is small algae rather than big stuff. I've never had anything big block a sprinkler. Only a build up of slimy algae type stuff (which the pipes are full of). I'm going to temporarily put the VANs back in again this week and see how I get on.


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## burntfire (Dec 10, 2020)

I'm totally spit balling here.. would it be possible to add a larger filter with a backwash back to the lake as a "1st line of defense" followed by a smaller particulate filter at your property? You could attempt a multi-layer filter.


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## mrdman (Mar 7, 2021)

I will look into multi-layer filters. Many thanks.

What is it exactly that is blocking the MP rotators do you think? The reason I ask, is pouring from the outside tap shows clear water, but with a bit of transparent specks if you really look hard enough. So is it that it passes through ok, but then when it rests in the pipe wet, the bacteria grows, turns into slime and then it becomes blocked? Hence why the insides of my pipes are so full of slime? 
Should I be looking into some sort of chemical solution?

I've been reading this:
https://s3.wp.wsu.edu/uploads/sites/2056/2014/01/Maintaining-Drip-Irrigation-Systems-Bill-Lamont-Penn-State.pdf


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## Chocolate Lab (Jun 8, 2019)

I called a couple of irrigation companies about my well water and a possible irrigation system, and they both said they don't recommend the MP Rotator-style heads for dirty water. But they said a rotor-spray type head should be fine.

Personally, I love the sound of impact heads... but maybe you or your neighbors don't, which I understand.

I was wondering if you couldn't try a spin-down centrifugal filter, the type you install in-line with your PVC and you just open the valve to flush it, plus you can replace the filters if need be... but I think those are more for sand and other sediment and might clog up quickly with lake sludge.


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