skippy pump math and other questions

[JessicaS]

Hi everyone,
I am planning on putting a pond in my backyard and after doing some research I have a few questions being new to the modern pond world. So prepare to be bombarded with sketches, pictures and questions!
Goals and Site considerations

• I want to put a pond in my tiny! backyard. The area is appx. 14' x 6' and I would like to leave some room around the edges for plants. So the pond could be a rectangle with vertical sides measuring 12' x 3.5' x 3-4' deep which is around 950 - 1000 gallons.
• Obviously the size of the space limits me from putting an external bio-filter area and water features so I was hoping to do some sort of hybrid. I'd like 2 trickling pillar fountains w/ plants in the top at either end of the pool. At 18" square rising 2-3 ft from the water they would each be about 100 gallons. I have some thoughts/questions below about making these skippy style filters.
• I want to put 3-5 butterfly koi in the pond, from my understanding koi require: min 1000 gal, a bottom drain, a prefilter to remove solid wastes, a heater for winter weather, a large bio filter, 4'+ depth. I realize my pond would be on the shallow side but I am pretty urban and could easily net the top to protect from predators.

On to questions

1. My main confusion is the size of pump I would require if I make the columns skippy filters. Each would be 100 gal (200 gal filtration total). If the pump is turning over the water 12x per day - then 250 gal/hr would be going through each filter with a retention time of 24 min. That is pushing 4-5 gal out the top of each planter (is that a trickle? I don't really have a concept of how it would look). Assuming each pillar is half submerged the pump would be holding 100 gal of water above the surface of the pond. How does that affect the head of the pump and therefore the size of pump I require?
2. With 200 gallons of skippy filters for a 1000 gal pond am I totally overdoing the amount of filtration I need? I thought maybe another way to make the columns filter was to have the submerged part act as a skippy filter and the above water part act as a trickle filter. The water would then exit the column at surface level. Pros? Cons? And what size pump would I need if this is the better option?
3. I was a little worried since there is no waterfall about there being enough dissolved oxygen in the water for healthy fish and aerobic bacteria. I thought it would be a good idea to install airstones in the bottom of each column. Thoughts on whether this is a good idea?
4. Are 2” pipes a good size for the system?
5. Is my bottom drain going to have enough flow to move the solid waste to the pre-filter?
6. The pre-filter needs to sit at the same height as the surface level in the pond, correct?
7. Am I missing anything important?

Sorry if these are lots of repeat questions from other threads and thanks for all the help!
Jessica

 

[Waterbug]

You don't need a water heater in Maple Valley, WA by a long shot.

3-5 Butterfly Koi is probably too much for 1000 gal without upping the bio filtering. Skippy type filters aren't great. Trickle Tower, Bakki Shower filters are 30+ times better at converting ammonia for the same size. So better to just have Trickle Tower or Bakki Shower type filters. Plus you'd pretty much never have to clean these while a Skippy could require weekly, monthly or certainly yearly cleaning which is not fun. But for say 5 Koi you might want to add a few more. It's impossible to say of course. Filter requirements depend on the amount of food fed, not number of fish. Some people feed a little once a week, some people feed 4-10 times per day. So I'm just guessing. But if I wanted 3-5 koi, and given your small space, I'd design as much bio filtering in as I could. People with large areas can always slap together a few more 55 gal drums as filters if needed hidden behind the barn or whatever. In tight spaces that isn't normally possible or desired.

Another option is a trickle water change where water is dripped into the pond 24/7 and some rate between 10% per day (high fish load) and 10% per week (lower fish load). You have to build an overflow to carry away the extra water. If you normally irrigate this extra water can be directed for that use. But in small spaces that can be a problem. This type of filter is very good.

Depth of the pond doesn't matter much to herons, they can pick the fish off the surface. You might consider building a permanent structure over the pond to keep out herons. Just being able to string fishing line 10-15' above the pond can be very effective. It may sound easy to just net the pond, but in practice...not much fun.

You measure pump head from the pond surface to water surface in the tank, or where water comes out of the pipe if that's higher than the tank's water surface. Depth of pump has no effect on head. Pipe diameter would be the other consideration, but much less of an effect (normally) than head.

Pump size depends on two basic things. Aesthetically how much sound and movement you want. For small enclosed areas I suggest designing so you can adjust sound later. Second issue is fish load. Higher the fish load the more water movement needed to exchange gases and move waste to bacteria for conversion.

Gas exchange happens at the surface. While most people think waterfalls and fountains are needed that isn't true. Having a pump move water so bottom water comes to the surface is more cost effective. Air pumps are also cost effective, but again, it's not the bubbles, it's the bubbles pushing water from the bottom to the surface. Trickle Tower filters are effectively waterfalls.

2" pipe...depends what it's used for. Bottom drain, nope. Pump, probably more than needed but that depends on the pump. From the skimmer, probably OK. For TPRs, probably too large.

Bottom drains require TPRs (Tangential Pond Returns) to push debris to the hole to be effective. In your shaped pond you would require 2 or 3 bottom drains and several TPRs. I think it would be better to move the BD to one end and have what is called a river flow BD. The TPRs are placed at the opposite end basically. But I didn't look too close at your plans. I will later if more detailed info is needed.

Pre-filter elevation depends on the type of filter. I didn't see your plan for this.

Didn't notice a skimmer. They're great.

If you do end up having water from the filters fall to the water's surface I like a catch basin there. That keeps the water surface still for better fish viewing and also collects any foam so you never have to look at foam floating on the pond. And the water from the basin can be directed at the bottom acting as a TPR. I call that win, win, win. Just takes a little design and almost no cost.

 

[j.w]

Jessica
You are a neighbor down south of me! Love that photo of the trickle towers. I'd like to add at least one to my pond..................I'm still in the thought mode on how to do mine

 

[capewind]

Waterbug... how do you size a trickle tower to a pond? For sake of arguement, say there is an average fish load (not high/not low load/down the middle)... Hubby has a spare parts trickle "filter" on the 750... it was a marine wet/dry... it has a spray bar, and "trickles" water over media that is not submersed in water... so I "get" that part, just not how to size it...

While I am wondering for outside, thinking of the 750 inside too, I was wondering about using a 35 gallon plastic trash can on a stand next to the 750, with a simple 2" pvc pipe near the bottom of the barrel for the return... what size pump would be in the ballpark? With the 750, assume over stocked, and over fed, substancially (aka as the babies grow).

 

[koiguy1969]

i keep 5 large koi 18" - 2', a large pieco and 100 - 200 of 1&1/2" - 5" koi in 1200 gal pond with a 70 gal skippy...do it every year, and have been it for years..trouble free....i currently have those 5 large koi, the 18" pieco and 78 2" -5" koi in a 800 gal basement wintering pond with a 55 gal skippy...also been doing this for years no problem. i do this every year and sell koi every spring. have yet to even treat a sick fish let alone lose one to anything but a heron. as far as flow rate, i circulate my ponds volume once an hour thru my filtration. plus some additional circulation for aeration and water movement.,,,, i'm not saying that a skippy is best, just saying they can do the job, and do it well..atleast mine do.

 

[capewind]

Koiguy,

I remember what you have in your 800 What size pump are you using with the skippy? Presently in the 750, we have 107 babies... Most are 3-4" with 2 closer to 6". So far, so good with water quality staying good with the hodge podge on it, but want to give hubby a nudge to up it (and simplify it too). We have a spare (and clean) 35 gallon barrel, so *I* need to have better understandings to give him that nudge since this is all basic common sense to him LOL.

 

[koiguy1969]

i run a fishmate 865 gph pump on my skimmer / fines filter. the pump pulls it thru the filter it's discharge is venturied into the pond for aeration and circulation..and a prefiltered 1000gph tetrapond pump thru my filter in my basement pond. outside i run the same 1000gph pump thru my filter and a 2100 gph pump venturied into the top of the filter for aeration and circulation...making my waterfall around 3000 gph. my pumps are always prefiltered.
https://www.gardenpondforum.com/top...-my-simple-but-effective-basement-pond-setup/

 

[capewind]

Thanks for answering my questions Koiguy... I am totally confused and then some now... with you talking about two ponds, I got lost, so got hubby to read this thread, and also showed him pics of your system... and then he tried to explain it to me... he even drew pictures... so now I have forward/reverse osmosis. upflow/downflow, aeration, etc clouding my head even more LOL.

He said the trickle tower filter concept is good, but it would have to be gravity fed through a skimmer with a pump in the sump of the trickle filter to pump back up to pond height, thus reducing head pressure?????????????????????????????????????????????????????????????

When all is said and done, he said he likes the skippy better, venturi fed... and in English for MY benefit, told me to think of the skippy as a giant auquaclear LOL. Oh, and he did take my hint to get on upping the baby ponds filtration to make me feel better

Going to shut up now so you all can stick to the OPs questions, and I'll just try to follow along LOL.

 

[Waterbug]

Waterbug... how do you size a trickle tower to a pond?

The same way every filter has to be sized. You guess at the initial size. Then you test water from time to time.

In most ponds small fish are added so you generally start with a way over sized filter that you think the fish will grow to need. Maybe some fish don't make it, maybe some fry live, maybe you add some more fish. Pretty much impossible to know what will be needed.

For some ponds, the owner knows they are going to add X number and size of fish on day one and know exactly the amount of food that will be fed. In those cases there are ways to estimate filter size. But that's well beyond what people here would want to do I think.

 

[Waterbug]

He said the trickle tower filter concept is good, but it would have to be gravity fed through a skimmer with a pump in the sump of the trickle filter to pump back up to pond height, thus reducing head pressure?????????????????????????????????????????????????????????????

It can be difficult if difficult is desired. But a Trickle Tower is just a pile of rocks and you pump water to the top. There's no hidden buts, extra pipes, cables, etc. Pile of rocks + water = done. Many people do like to try and make their setups more complex with spray bars, fans for blowing in more air, special vents, you name it people have probably tried it and posted that it worked way better...but of course they never test the actual result. They just know in their gut their special improvement worked wonders. People who actually test these things have never found any of these tweaks to make any difference. The main improvement to the Trickle Tower is the Bakki Shower. But for most people Shower filters are way more than they need, are too noisy, and maybe too expensive to run.

Yeah, you could dig a hole and have the Trickle Tower below ground and have a sump pump, etc. but I don't know why anyone would. Maybe to hide the filter? I've never seen one built that way.

The whole pump/plumbing/head loss complexity is true for any filter. The advantage of picking a higher efficiency filter is you get more of what it is you're after, ammonia conversion.

 

[capewind]

For some ponds, the owner knows they are going to add X number and size of fish on day one and know exactly the amount of food that will be fed. In those cases there are ways to estimate filter size. But that's well beyond what people here would want to do I think.

My thought for the QT is what I already know. 107 baby koi, at a present average of 3", expecting them to grow 6-8" by spring when they can either go outside or be sold (extras). At some point, we will likely reduce the number in the 750 by half, but am wondering about a size assuming they were to all stay in the 750. AKA interested in building something for the max capacity that I could potentially keep fish in long term. Guessing they get a cup of food each day (two large handfuls, one in the morning, one at night).

Now between all the different pics he drew for me, I am soooo lost now. With a "pile of rocks" does that mean this was NOT the one he was explaining needed a solids seperator at the bottom?

Unlike you all, I can not wrap my head around formulas... I need to hear x size would work for xxx gallons with an average fish load.

Hubby's answer to most of my questions is when you think you have enough filtration, double it LOL. (That may be a personnal jab at me LOL.)

 

[koiguy1969]

you cant have too much filtration! better to have it and not need it than to need it and not have it...its that simple!!!

 

[capewind]

Yes, but there is a line between need with some wiggle room and total over kill LOL.

I'm one of those people who has a good understanding of a LOT of subjects, but then there will be a subject, that no matter how hard I try, I just can not fill in the gaps, and I have that issue with filtration. I understand the basics of the nitrification cycle, but not how to factor a load, verses room for nitrifying bacterias to grow. It sounds pretty simple, but my mind is spinning with the BUT... for ONE well fed fish (whatever size), would need XXX cubic inches of surface area for bacteria growth to effectively handle the load of said fish.

When I try to research it, either the available info is too vague and doesnt answer the question, or is so complicated, I get lost in the first few sentences LOL. I know I am over thinking the subject, but trying to understand a basic formula/guideline...

 

[koiguy1969]

its more the amount of food fed to the fish than the number of fish....one cup of food makes approximately the same amount of waste wether 2 fish or 4 fish eat it. if a filter catches the wastes and holds it, and not cleaned, its the same as if it were left in the pond. may be even worse because theres a flow of water thru it so it can physically break down quicker. thats why a seive filter is so nice. the water flows thru it and the waste is removed from the water all together. i use easily cleaned prefilters and clean them regularly; about every 4 - 5 days.

 

[capewind]

So this IS getting complicated... aka the quality of food (usable nutrients verses wastes)...

Isnt a seive filter like a solids or sediment seperator?

One of the pictures hubby drew for me looks like a barrel... heck, will post a pic of what he drew... WHICH type of filter is this? I think it's a trickle tower??? But reading WBs response, he was saying a tickle tower was basically water running over rock (or whatever media)... would a trickle tower have a solids area?

Isnt a skippy built the same way, but higher water level?