Skippy biofilter conversion

Conversion..... Hmmmm, perhaps this should be posted under the religious section......

This year I decided to convert my 150 gallon Rubbermaid stock tank into a biofilter for our 2300 gallon pond. Previously the stock tank has been used as a combo-settling chamber for fish solids and a veggie filter. The veggie filter (water hyacinths) coupled with many plants in the pond used to do a pretty good job of keeping my water clear. “Used to”…. Raccoons have been a major problem recently dumping many of my potted plants into the pond and eating most of the water hyacinths. That, coupled with a neighbor giving me a bunch of his goldfish, has resulted in lack of water clarity all last summer and winter. I don’t want crystal clear water but it would be nice to see the fish again…… Here’s my conversion of the stock tank into a skippy biofilter…..

Below is the floor of the stock tank. The drain on the side was about ½” above the bottom. The remaining black stinky fish solids would have to be vacuumed out whenever I drained it. It was a pain. I poured a mix of concrete and raised the bottom so that it now drains pretty well and only takes some spray from the hose to clean out any remaining stuff.


The black ABS is a venturi that our son made for me several years ago. The venturi aerates water entering the pond. I thought surely the backpressure from expelling water near the bottom of the stock tank would force water out the hole in the venturi but it doesn’t. I will leave it up to an engineer or physicist to explain…..


I painted the concrete to seal it and make it smoother. The white pvc cap on top of the venture acts as a muffler. The venturi makes a noticeable gurgling sound as it draws in air into the water and the cap muffles that sound. On the bottom of the stock tank I placed the black ABS saddle shown in the following photo. The discharge pipe will rest on top of the saddle to hold it up several inches from the bottom and also help support the weight of the discharge lines.




Below is the discharge piping in place to make a gentle swirl action.


Below shows the added grating that will support the biofilter media.


Gene at Koi Village suggested I use Savio Springflo as my biofilter media. This media is ¼” wide ribbon-like material with ripples in the ribbon. To contain the media I used tree bird netting that I cut to the appropriate size and then I used zip-lock ties to “sew” the edges together to make pillow-like containers to hold the media. I made two of these, one for each side and stuffed them with the Springflo media.




On top of the biofilter media I placed egg-grate lighting grids to hold the material down.


Green water? What green water? I put bricks on top of the egg-grating to hold them down. You are supposed to put more media such as commercial floor scrubbers on top to add additional filtration and biofilter action but I have chosen to see how what I have works first….. Baby steps…..

Looks good Mikey, how long before the bacteria begin to grow or did you add some?

That looks pretty much like mine. EXCEPT, Pete plumbed into the tank near the bottom and we have a stainless steel spillway at the top that we got from Gene. It's made specifically for 100-150 gallon Rubbermaid tubs. Also, Cindi bought her grid from them. It is much heavier than the grid you and I used and already cut to shape. I put one grid near the bottom on the second ridge then layers of floor scrubber pads, and then another grid. I find them much easier to handle and clean as we have to shut ours down every fall and clean the whole thing. Pete added in a bottom drain last year for easier cleaning. Although it wasn't so bad with the shop vac. I guess I don't understand the use or need of the venturi.

Bullfrog: From what I understand it takes a couple of weeks for the microbes to kick in and make a difference. I didn't add anything to jump start it.

Esther: Water going into my biofilter comes from the bottom drain in the pond. Water on the bottom is supposedly less oxygenated. The venturi oxygenates the water which helps the microbes on the biofilter media.

Bullfrog, Mikey doesn't need anything to jump start it because he is using this on an existing pond. The little critters are already in the water and will quickly set up shop in the media.

OK Mikey, we don't have a bottom drain on the pond. Our pump sits in a laundry tub/skimmer inside the liner so pulls from the surface.

Janice, mine is pretty much the same as Mikey's. Just water comes from the skimmer at the other end of the pond into the bottom of the tank just like Mikey's. Pete put the two exits facing away just like Mikey did. Oh and I don't have the venturi either. We have the cleanout valve on the back of the long side and the spillway at the top on the other side. Here's the grids and the PVC frame that goes inside ours. You don't want to see our Skippy now. We just shut off the pump and never took out the stuff or cleaned it. The stainless steel spillway has a piece of slate covering it.

Yah, that can be a problem. We just squeaked ours between the pond and some rose bushes and a tree.

Looks like a very nice setup Mikey and you made it all yourself.

How does that song go....."had a little help from my friends". All I did was copy someone else's ideas/plans.....
http://www.skippysstuff.com/biofiltr.htm

Me too Mikey. Skippy is dead. Did you know?

Are you pulling my leg Esther? The only real Skippy I know of is the peanut butter.....

No Mikey. Skippy is the guy who came up with the idea to use the Rubbermaid tank. He lived in Detroit. I'm gonna look at the Skippy site and see if it tells.

Mikey, I emailed the Skippy website. I am wrong in a way. Skippy is a 7' frog that was their "mascot" for a while. But one of the owners who documented using a Rubbermaid container for a biofilter and put the instructions on their website was one of the owners who passed away a few years ago.

Seven foot frog.........

It was a statue of some sort that was in front of their business for a while I guess. It's name is Skippy.

Hey Mikey and Esther,
After snooping throughout the internet and watching many you tube videos I have come to the conclusion that one would be able to build a skippy most any size and out of a large variety of containers for different applications. My pond has a completely different filter set up, but it works great. Mine is more of a skimmer/pre-filter that pumps up to the sprinkle down boi-filter that flows back to the pond.

Happy ponding,

Oh sure. The Rubbermaid tank is just a container. I had made one out of a 5 gallon bucket one time for a tiny pond.

I guess one only needs is a good imagination, and some old fashioned know how. You're good at that. Most everything in and about my pond is home made, seems to be working just fine.

Happy ponding,

We put a spiggot at the top of the bucket so we could control the amount of water going in. Then it gravitied out by itself. But we learned we had to sit it on some plastic so that if it ran over, it wouldn't empty the pond.

Esther, that makes sense. In the overall pre-design of how I was going set up my pond and filter system, I under shot the target by not having enough filter. At first, all I had was the skimmer/pre-filter type reservor next to the pond. I quickly found that I was having to clean the single filter every day. As I read through one of the other forums and asking many silly questions, I found that I was way off track on what I thought would be an adequate DIY pond filter. Right after that I installed a Lowe's UV clearifier only to find that I was still cleaning my filter everyday. I have since modified the pre-filter with a real course filter material which did not clog, and would let the water flow through it. Then came what I was convinced I didn't need. (I'm a stuborn like mule). I made a DIY 27 gallon trickle down boi-filter. Gee, it's amazing how simple things can be when you know what you're doing. Now my pond water is quite clear, and the skimmer/pre-filter in the reservor next to the pond only needs to 'rinsed' about twice a month, sometimes once a week.
It's all thanks to fellow ponders like you guys that enjoy sharing their ponding skills.

Happy ponding,

I also use three types of prefilters. I have 4-6 Black Knight brushes that hang from a PVC pipe that catches the larger gunk. Then is a layer of course media and finally a double layer of media that catches the fines. The brushes are so easy to clean with the hose and reduce what is being caught by the finer layers that are hard to clean. It just depends on what is going on in the pond as to how often I have to clean them.

Looks good Mikey, how long before the bacteria begin to grow or did you add some?

The pond is officially clear of suspended algae. The water started clearing about 5 days ago, thus it took about 3 weeks for the microbes to develop to the point that I noticed a definite change in clarity.

I still have not used the pond vacuum because I wanted to actually be able to see the bottom... Hopefully I will find time next week to vacuum the pond and then add some enzyme stuff that is supposed to eat the sludge that develops.