Floating skimmer for my small pond

[crsublette]

I became aggravated at the performance of "in the wall" skimmer since my pond is in a very odd shape, with a fountain in the center, and other obstructions that only allows the "in the wall" skimmer to effectively clean about 20% of my pond's surface water. Thus... the reason for my desire to have a floating skimmer...

Floating skimmers are also called, No Niche Skimmers (https://www.google.com/?gws_rd=ssl#q=no+niche+skimmer).

Since my pond is more of a water feature than a pond... it is quite small... and too many retail floating skimmers are 4~6 inches wide with a depth of 11 inches... I didn't want this big ugly skimmer thing smacking me in the face each time I want to admire my water feature pond.

Here are some examples of a No Niche Skimmer (i.e., floating skimmer) ... trying to make a smaller one of these that I hope is less obvious.

Video below is not a floating skimmer, but I like the "no fish" trapping potential of this one... I can see this easily being adapted to be a no niche skimmer.

 

[crsublette]

http://i458.photobucket.com/albums/qq304/SkybeeX/NCM_0093_1.jpg

http://i458.photobucket.com/albums/qq304/SkybeeX/NCM_0090_1.jpg

http://i458.photobucket.com/albums/qq304/SkybeeX/NCM_0083_1.jpg

Quick scan of my scribblings showing the plumbing schematic....

http://i458.photobucket.com/albums/qq304/SkybeeX/SCAN0012_1.jpg

 

[Meyer Jordan]

Judging from the diameter of your skimmer I assume that you don't have any large leaf trees near your pond. Or many trees near the pond at all.

 

[crsublette]

Keep in mind... a floating skimmer should "float"... in otherwords.... does not stay in one fixed position... in other words... the skimmers height adjusts with the height of the water level... but there needs to be a significant enough elevation change inside the skimmer versus outside the skimmer to so allow sufficient skimming force, that sucks in debris into the basket.

You can not have too much buoyancy since you have to have that elevation change between the inside and outside of the skimmer. Since I lack the proper educational background to do this the easy way, I had to use the "try it, trash it, do it again" approach...

I used pipe insulation foam, strapped with a zip tie, to act as my float. I constantly added and remove small pieces of foam from the zip tie until I finally obtained the proper buoyancy. Do not forget the gravity created by the suction force inside the skimmer; this gravity will be different for everyone unless everyone has the same net positive suction head (NPSH) at the skimmer, which is incredibly unlikely.

In the schematic... SL means "slip"... SP means "spigot"... Sch40 is your typical PVC pipe... Sch20 is thinwall PVC pipe.. Sch20 has the same outside diameter as Sch40, but different inside diameter, less tolerant of high pressure, and tremendously cheaper than Sch40.

Differential at the ' T ' between the 1.5 inch to 1 inch pipe increases the "low pressure" so to allow for higher suction...

Differential at the 1 inch to 2 inch allows me the 2 inch Sch20 pipe where I place my trash basket... This differential also allows more water to accommodate the suction force so I prevent that typical "toilet sucking" noise experienced with floating skimmers...

"Trash basket" is a NFT (nutrient film technique) basket used in my aquaponic growing... This skimmer uses the 2 inch one, which sits perfectly inside a piece of 2 inch pipe (both sch20 and sch40)... http://theaquaponicsource.com/product-category/build-your-system/net-pots-bags-plant-holders/ ... You can create your own basket, but this is the materials I had on hand...

 

[crsublette]

Judging from the diameter of your skimmer I assume that you don't have any large leaf trees near your pond. Or many trees near the pond at all.

Only elm trees, which have small leaves... I don't have any oak trees or such that have large leaves...

This floating skimmer would definitely have to be adapted to use a 5 inch basket of some sort so to allow for large leaf trees.

 

[MitchM]

What is the purpose behind having the skimmer float?
It seems like one more thing that could possibly jam and fail.
I guess it would give you more time between topping up from evaporation.

 

[crsublette]

My awkward little pond will have 4 of these skimmers scattered about... they are all connected to the suction force of the same pump... there is a secondary bottom drain so to prevent pump cavitation...

A good way to know if cavitation is occurring with the pump is to... install a compound pressure gauge (that is a psi gauge showing both vacuum and positive psi)... find out the Vapor Pressure variable for your water temperature, subtract this from this compound pressure gauge read... then... reference your pump's Net Positive Suction Head capability, as determined by the manufacturer... the compound pressure reading minus vapor pressure cannot be lower than the pump's suction capability... if it is, then cavitation will occur and will ruin your pump.

Due to the 1 inch differential, this has allowed my bottom drain to act as the secondary suction thus allowing it to make up for the lost suction whenever my skimmers are no longer sucking.


Biggest disadvantage... since I am using 2 inch trash baskets... I have to dump these more often... I am thinking about using one of my 3 inch baskets instead to see how long I go before dumping them.


Definitely going to be a leaf net over my pond for the upcoming season change.

 

[crsublette]

Unintentional... although cool... you can see the suction force water ripples in the 3rd picture above... each of these skimmers have a 18 inch suction diameter... this plus my water jets in the water creating a rotating current... cleans the pond well enough for me... but... since I still enjoy my rock wall, there are leaves that get stuck in there until I dislodge them with a spray of water.

 

[crsublette]

What is the purpose behind having the skimmer float?
It seems like one more thing that could possibly jam and fail.
I guess it would give you more time between topping up from evaporation.

Tremendously easier to install... doesn't have to be in a fixed location... Multi-functional (in the winter they will be angled into the pond)... I can move or remove them whenever I want... No freezing concerns...

"in the wall" skimmers are fine... but... meh... not for me on this pond...

 

[MitchM]

Are the skimmers plumbed with flexible tubing if they're not meant to be in a fixed location?

 

[crsublette]

Planning on putting some led lights on the floaters... to add some fun "ambiance" and to light up the pond underneath a bit.

Definitely are limitations to this... Although, I think will be easy to adapt to fix.

Definitely have my kinks to work out... but works great for me...

 

[crsublette]

Are the skimmers plumbed with flexible tubing if they're not meant to be in a fixed location?

Definitely an easy adaptation to add... currently, in a fixed location due to materials I am using... sch20 pvc is incredibly cheap... I have already spent about $100 in wasted PVC pieces trying to figure this out ... 2 inch and 3 inch sch40 PVC parts are not cheap!! ... which is so silly since it is so easy now that I find out how to make it work...

If you do use flexible tubing... be sure to anchor the skimmer... the suction force often times would even pickup the PVC pipe that I was using...

 

[crsublette]

I was just happy I got it figured out and wanted to share...

Will post updates as I improve the skimmer and share any further limitations that I discover...

and I will definitely share if the entire project becomes scrapped if it just pisses me off..

 

[crsublette]

Forgot to mention... I also have some "rock tape" (is what I call it).. which is just basically black pvc wrapping tape.. I will adhere some crushed gravel and decomposed granite to it and finish it with a clear sealer to make sure nothing comes loose... I will post pictures of this once I get around to it.... Going to use this to try to camouflage the skimmers pipe work.

 

[crsublette]

Quickly want to mention...

Trash baskets are entirely unnecessary as well if you are using a Zakki Sieve Pre-Filter (http://www.deepwaterkoi.com/Zakki-Sieve-The-Direct-Suction-Pre-Filter-Zakki-Sieve.htm).... just had to throw this out there... I almost forgot about this since the Zakki Sieve I have has been repurposed for a small home trout aquaponic system (will post this soon).