Mechanical filtration choices discussion.

[crsublette]

Are perchance any of you gentlemen engineers by profession? I showed this thread to my husband, who is an engineer. I was mindboggled. I am a mental health therapist and my background is clinical psychology. So I can tell you all about classical and operant conditioning, associative learning, group social dynamics and so on, but I couldn't have been more baffled by Charles' setup if he had described it in Chinese.

While cost is certainly an issue, simplicity is an even bigger issue. When I set out to do the pond, I made it clear to my husband that it would be my project and my hobby, and I'd only solicit his help when absolutely necessary.

Eekk... I feel quite imitidated and paranoid now. You might know more about me than I know about my self. I enjoy the psychology subject, it was my favorite class in college.

 

[Litzi1964]

Designing and constructing something like Charles' setup is totally beyond my capabilities, although I must say it sounds impressive.

Barring problems caused by mishaps or human error, my system is pretty easy to maintain. Since my pond isn't even 2 ft deep getting in and removing the box filters and hosing down the filter media isn't that hard. It's maybe a 10 minute job. It takes less time than cleaning my parrot cage and it's nowhere near as unpleasant as cleaning my cat box.

 

[crsublette]

Yeah, Howard, with the help of your explanations, now I am starting to better understand on how the earthangroup's radial flow filter works. It is due to the water being "straightened" out, without having a big area of space to do it, so to reduce the turbelance well enough that will allow the particulates can settle.

I looke forward to see some pictures and possibly a video of showing your type of laminar flow SC achieving results.

I can see how the concave plate in my previous pictures will just disperse the turbulence rather than smoothing it out. So, I think I would build it to reflect what has worked with the radial flow SC as shown in the attached picture below.


For anyone curious, the video in the radial flow SC shows this SC working quite well, but the flow rate can not be too high. If the flow rate is too high, then this would increase the turbulence preventing the particulates from settling and increasing friction loss. As by the info in the radial flow hyperlink, an approximate coefficient of 5 gpm per square foot area of the container, that achieves around a 30 second to 4 minute retention time, is needed to allow the particulates to settle. This would be around 75 gph (30sec retention) ~ 600 gph (4min retention) for a 5 gallon bucket. So, a 5 gallon bucket would be just perfect for many small ponds.


Equipment/Material list:

1 foot length of 6" PVC pipe (might get it for free from a hardware scrap pile)

A transitional pvc glue to do a chemical weld or other sealants or adhesive to try to make the straightened, bent PVC piece to adhere to the bucket's walls to stay in place.

Hole saw set (which will come in handy for future DIY projects)

Around about 4 feet of 1" pipe

1" adapters to connect through the bucket's wall and P&L or 3M-5200 marine adhesive to make a good seal. Be sure to let this cure. For the adapters, could use plasic electric conduit, uniseals, a true bulkhead, or bolt through flanges, which you can find and you think would work best.

2x 5 gallon bucket

2x Gamma seal lid

Quilt batting.

Valve for the drain.

Hole saw set is really just a one time cost that will be useful into the future if folk like to DIY stuff.

+ $20~50 -- 1" adapters and valves total cost depending on the type of adapters and valves

+ $33 (including potential shipping cost) for 2 gamma seal lids.

+ $6 for total of 2x 5 gallon buckets.

+ $10 for adhesives.

+ 1 foot of 6" PVC, around $12.

So, total would be around $80 ~ $120 plus personal time involved in building it and assuming ya will not screw up.

It could cost $50~80 less if the materials are already on hand or can get it for free somewhere.


Since it is built to exactly replicate the earthangroup radial flow filter, except in a 5 gallon bucket, then I bet it would work as long as the flow rate is correct as mentioned above.

Plus, these two filters can be easily hidden somewhere or buried in the ground since 5 gallon buckets really are not that big at all. Due to the size of the buckets, I would imagine go longer between cleanings, but I would not wait long just because it can be done.

 

[crsublette]

So, DIY'n can be expensive and I would not do this type of setup.

If it were me with a small pond and do not mind spending the time to clean the batting and other materials involved, then I would likely just do a version of a dinky little simple pre-filter for large particulates, use my pond vacuum occasionally to suck out the big debris, then have this water exiting from the pre-filter going into the quilt batting polishing bucket or a simply tray of quilt batting, then have this water trickle over some lava rock or into a retail product such as Tetra's 500gal wet/dry trickle bio-filter.

 

[crsublette]

As folk may be aware, there are pre-filters for gravity flow systems and pre-filters for pump fed systems.

A filtration system is considered "pump fed" whenever the water is initially pulled from the drain by a pump and then the pump pushes the water into the filtration system.

A filtration system is considered "gravity fed" whenever all of the plumbing and filtration is below the pond's water level so that the weight of the water and gravity is what pushes the water into the filtration system and then, at the very end of this system, a pump might be used to feed pond returns, a stream, waterfall, etc.

Gravity fed prefilters are the settle chamber and sieves. Most sieves are for gravity fed systems.

Pump fed prefilters are enclosed, pressurized, leaf baskets or pots or a sunction side sieve. The only sieve I am aware of that can be used on the suction side of the pump is the Zakki Sieve, that is referenced in post#6 and in post #28.

You can easily DIY an enclosed, pressurized, leaf basket. Here are a few hyperlinks that explains one particular approach to implementing this.

No-Clog Leaf Basket Prototype - jump to post#66 and click on the mp4 videos to view it in operation.
55 Gallon Leaf Basket prototype
30 gallon giant leaf basket

 

[crsublette]

Picture below is how a 5 gallon bucket could be made into a suction side pre-filter.

A vacuum would be created in the bucket that allows the water to still be pulled in from the drain or inlet.

A more sturdy material might need to be used so that the bag does not come up and clog the outlet.

To get a better seal on the gamma seal lid, then you can try putting strips of weather stripping below the gasket and put some silicone or vaseline on the gasket O-ring to help it seal better.

 

[crsublette]

Here is also another good thread that talks about various pre-filter options, for the suction side of the pump, at would this make a good pump pre-filter.

 

[crsublette]

Also, for anyone curious, the goal of pre-filters is not to capture suspended particulates. The goal of pre-filters is to capture the big debis before it clogs up the pump and the remainder of the filtration with big debris. Polishing filters, such as quilt batting or S&Gs or finer sieve screens or finer sock sieves, are used to capture the suspended particulates.

There are 2 stages of particulate mechanical filtration. Stage 1 for the big debris and stage 2 for the smaller debris. Of course, both of these stages can be combined in a single filter, but this type of filter would have to be cleaned out at a much higher frequency.

 

[JohnHuff]

Also, for anyone curious, the goal of pre-filters is not to capture suspended particulates. The goal of pre-filters is to capture the big debis before it clogs up the pump and the remainder of the filtration with big debris. Polishing filters, such as quilt batting or S&Gs or finer sieve screens or finer sock sieves, are used to capture the suspended particulates.

I have found that pre-filters will capture suspended particulates. What happens is that the pre-filters capture big debris, the big debris will clog the pre-filters a little and capture the medium sized debris. That in turn will clog up the pre-filters to capture the small debris which will then capture suspended particulates.

 

[Mucky_Waters]

I have found that pre-filters will capture suspended particulates. What happens is that the pre-filters capture big debris, the big debris will clog the pre-filters a little and capture the medium sized debris. That in turn will clog up the pre-filters to capture the small debris which will then capture suspended particulates........

Yes, that works for short while, but then it plugs up and water stops flowing through it.

 

[JohnHuff]

Well, that happens to all filters.

Yes, that works for short while, but then it plugs up and water stops flowing through it.

 

[crsublette]

I think the point he is making is that you will get longer and better use out of a filter that is designed specifically to be a polishing filter versus relying on a mismatched filter to clog so for it to eventually become a polishing filter and the mismatched filter will likely entirely clog much sooner.