HOW DO YOU CALCULATE WATER FLOW FOR SKIPPY?

Mmathis

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I read where a lot of you say you have "this much GPH going through your filter," etc., etc.

How DO you calculate what goes through the filter?

And, how do you know what is optimal for maintaining the biofilter? How much water, how long for dwell time.....

Have our SKIPPY up & running, but it's in a temp. location, pondside, until we get the waterfall built. When we first turned on the pump......whoa! Had to back it down via ball valve. Really powerful! For now, it's going at a rate that "looks good."

Pond is around 3200 gal. / SKIPPY is 100 gal. / pump is 3600 gph [hooked to SKIPPY and a spray bar over the turtle part].
 
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Since each Skippy is custom it's impossible to pre calculate flow. Each type of filter material would resist flow differently as well as how the material was placed in the filter. The pipe going in and out can be used to compute flow, but only if the media could also handle the flow. And of course as the Skippy clogs with muck flow thru media would be further restricted. In that regard the slower the flow the less often you would have to clean the filter, but then also the more bad bacteria is grown in the filter than good bacteria.

You don't want the flow so fast that bio film gets washed off the media, but that's more of a media thing. Some materials don't hold bio filter very well even at low flows. So that depends again on the media you choose to place in the Skippy. There is no standard Skippy media.

Bio filtering, the conversion of ammonia and nitrite, is best done at high flow, water fall type speed. Waterfalls, streams, trickle towers, Bakki shower filters all use fast water and perform 10-30 times better at bio filtering. It keeps the bio film clean which allows new water with O2, carbon, ammonia, nitrite to get to the bacteria. In most ponds if you look inside of the pipe coming from the pump you will often see a brown film on the pipe's inside surface. That's bio film and is the best bio filter many ponds have. Always clean, from the bacteria's perspective, good supply of food, out of sun light. In many ponds that have small combo type filters that are cleaned once a year the pipe going to the "bio filter" is doing more actual bio filtering than the filter. The filter instead is the perfect home to bad bacteria, low O2, muck, decay, etc.

I have read many times where people say water in a filter should have some "holding time" but that makes no sense. Bacteria can't reach out and grab O2, carbon, ammonia, etc. These things have to be brought to the bacteria. Bacteria don't have little hands that if the elements are moving too fast they can't grab them. It's more like your lungs. Air moves in and out pretty darn fast, faster the when you need more and breath harder. I think this business about "holding time" is more of a self justification deal. Since water moves thru these types of filters slowly and the writer wants nothing but positive things they just say slow is better. But there's no science, studies or any basis for the claim. And you will never see any of these testing the claim. Easier to write something than to test something.
 

crsublette

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Bad bacteria isn't really a bad thing since they help with de-nitrification, unless it produces Hydrogen Sulfide and only takes extremely little O2 to stop bad bacteria from making Hydrogen Sulfide; these type of filters are often used in reef/coral aquariums. Other than that, I agree with Waterbug on everything else.

I actually emailed the people that invented the Skippy. They literally have hundreds of these filters setup everywhere for their pond farm. The idea is giving algae and bacteria a home instead of so much of it being inside of the pond. Their Skippy filters actually have a quite noticeable layer of floating algae on the open air top of their Skippy.

I emailed them to ask the same question. All they could tell me was what they thought to be the bare minimum, that is the flow should cycle your pond's water volume at least once a hour. They could not tell me if very high speeds made a difference. From what little I have read on koiphen.com, most on shower towers have a flow rate that cycles their entire pond volume 2 times a hour.

I would probably go for around 1~2 times a hour and have a venturi or some aerators setup to help add a little O2 (supposedly it's not much, but it's some O2).

So, from what I understand, your pump working at full flow of 3600gph for a 3200 gallon pond, is minimum, which is ok.

I think a 3600 gph pump typically use 1 1/2" to 2" outlet pipes. To slow the flow out of your spray bar, you can try bumping up the PVC size for your spray bar to like 3" or 4". Also, maybe raise your bio-medium a few inches more further from the bottom.

I finally finished my little 20 gallon rubbermaid trash can skippy. I used 3" PVC pipe for the spray bar. I put the egg crate lighting panel a 14 inches above the bottom of the can so then this gives me room enough for 1 foot of bio-medium (using k1/k2 and alfagrog mix). Then got another egg crate above this to prevent the bio-medium from floating out. I put a circle of 1/4" soaker hose a little bit under the bottom egg crate panel and this hose connects to my aerator.
 
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Bad bacteria isn't really a bad thing since they help with de-nitrification, unless it produces Hydrogen Sulfide and only takes extremely little O2 to stop bad bacteria from making Hydrogen Sulfide; these type of filters are often used in reef/coral aquariums. Other than that, I agree with Waterbug on everything else.
I personally don't have a huge problem with having Aeromonas bacteria in a water garden with inexpensive fish. On the other hand I don't want to spend time and money on a filter just to grow Aeromonas bacteria. I've never had a nitrate problem in a water garden and I can't say I've ever heard of a water garden having a nitrate problem. So I'll keep them in the bad category.

Seems like having a wolf guard the hen house to keep out the fox...when there isn't a fox problem.
 

crsublette

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Welp, not just to manage Nitrate, according to Mr. Norm Meck's catch 22 hunch, "prime candidates for the heterotroph bacteria that produce [the algae fighting] antibiotic are from the aeromonas and/or pseudonomas families".

A big deal about the special Bacteria House medium for Bakki House shower towers is that the cermaic media is made to help house some aeromonas bacteria. Supposedly, the ceramic media sharp edges to break down the organics so it can get to the anaerobic bacteria inside the medium is the reason why Bakki shower towers have huge DOC foam problems. I figure these fellas in japan able to afford the bakki house have some mighty fine fancy koi.
 
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I used to believe more in Norm's theory on bacteria producing the chemical and I certainly think it's still a good theory but the more case info I can get the more it seems like macroalgae is a better fit. Could be both too. I've seen some pretty clean ponds stay clear. Heterotroph bacteria is of course everywhere even in a spotless pond.
 

Mmathis

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So basically, once it's connected to the waterfall [once we get that built], all I REALLY need to be concerned with is if there is enough flow for the waterfall -- SKIPPY filtering will take care of itself.....? And if not enough flow for the waterfall, consider installing a larger outlet so I can crank up the flow [without worrying about the tank overflowing].

Sounds good to me, if I am understanding right.

ps -- When I installed the 2" outlet (100 gal Rubbermaid), I didn't put it dead center, where the "Rubbermaid" label is. I moved it over some 'cause I liked that surface there was closer to the top [by just a tad]. So if I needed to, I could just duplicate that drain on the other side of center and have 2 drains coming out.
 
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Welp, not just to manage Nitrate, according to Mr. Norm Meck's catch 22 hunch, "prime candidates for the heterotroph bacteria that produce [the algae fighting] antibiotic are from the aeromonas and/or pseudonomas families".
I was just reading about bacteria and fungi competing for food and often do so using chemical warfare. That makes me think Nitrosomonas bacteria should be on the table as producing chemicals to fight single cell algae as a way to compete for ammonia.
 

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