I figure, with 8 or so fish I need about 1675 GPH to be on the safe side.

Please stop me if any of this is misguided. Everything I know has been the product of frenetic research over the past few days.

I really need help with the skimmer box and the waterfall filter.

The skimmer box (where the previous pump was) is devoid of any compartments for special media, etc.. My inclination was to simply pack the area around the filter with some of that Poly-Flo Filter Media. I will also use a small suspended net over the entrance to catch larger stuff.

Does this sound right?

Is this a physical filter?

What "density" do I need?

My second question relates to the waterfall box. The water is pumped from the skimmer into the bottom of the box. There is 3/4" PVC that acts as a roof supporting two mesh bags of lava rock.

How should this box be laid out?

For example (from top to bottom):
1. PVC
2. Poly-Flo Filter Media
3. Bag of bacteria balls (Biological Pin Balls Bio-Balls).

?

Any help will be most appreciated.

I have a pond with all the same features but the capacity is a bit larger (1600 gal). My waterfall is a mere six inches (in fall) but the width is about four feet, though the pours coming off the falls are somewhat directed.

The larger the pump the more water you'll put over the falls... after calculating head loss the amt of water going into the biofalls box is the same as the amt of water going over the falls, measured gph. I like the deeper pour my directed falls give the pond -- lots of deep air bubbles it seems.

I use mag-drive pumps. The mag drive pumps don't use oil and I've had them running near continuously for three years without fail. Laguna brand, waterfall pumps.

First you didn't say how you were piping from the skimmer to the bio-filterfall box. If you can, use flex pvc since it reduces loss since it reduces 90 degree angles and such.

Next, I would be hesitant to "pack" the skimmer with too much filtration because the pumps always have to be primed with water. I would be cautious to put dense packed media all around the pump and taking up water space. Others may correct me here, but I know that I have a Savio skimmer (full size) and I have two pumps in the basin behind the basket. Each is rated for 3900 gph. Pulling that much water through with dense media infront of them, the water basin is behind (lower) than the pond. I've had to substitute the media for a less dense media. You might get away with it but you will have to check the filters and basket/net an awful lot.

I would just put more and better media in the filterfalls. I like Savio's green tape-like media. It's durable though a pain to get installed. If I understand your situation you have a pipe coming in at the bottom (what size might determine what size pump), a plastic (pvc you said) roof or grate (is this right?), then you're planning to store media with more media.

I didn't like using lava rocks my first year. They're too dirty to work with after the little crevices are plugged. I would skip the lava rock and use the filtering you listed out, but with plants atop the media. Plant in gravel-filled mesh containers and turn it into a real biofilter.

The plants that do well for me in the biofilter/filterfalls are water celery and any rush or sedge, parrotfeather.

Hope I got your setup right.

Bests,
Pondbucket

I wonder how termite damage to a flex pvc pipeline would materialize... how would you know, what would you see?

thanks for the rapid and detailed reply. you described my setup pretty well. A couple of questions: You stand by Laguna. I knew they are one of the more finely engineered brands but hadn't considered it. Up till know i had pretty much been planning on a pondmaster 3200. Not that I know the first thing about pumps but i do peruse the forums pretty religously and pondmaster was a name that people swore by over and over again.

I now agree with you completely on freeing the skimmer as much as possible to facilitate flow. It is confusing to me that the "skimmer" plays only a cursory role in the filtering process. Or at least it was until I began to think of the waterfall (weir?) as the principle component (at least in my limited setup).

The pipe carrying water from the pump to the waterfall box is two inch corrugated pvc. It connects to the waterfall box on the backside of the box at the very bottom.

So what type of media )if any) would you place in the skimmer?

Assuming lava rock is out how would you try to foster the "helpful bacteria."

Oxy-Balls? Or whatever their called?

I agree completely with the top quality poly flow media.

I really appreciate you're help on this!

Thanks,

Donald

In my skimmer, there is a built-in basket and a filter that is rather coarse. I just use it as my mechanical filter to keep the bigger stuff out of the pump and pond. I clean this filter every few days, depending on how quickly it starts clogging.

In my filterfall box, there is a denser filter in the bottom, on top of that I have 2 large media bags, one filled with plastic scrubbers most people use to clean pots and pans, in the other bag are about 30 bio-balls and a bunch of the body wash scubbies that I took the little rope thingy off and stuffed them in. Floating on top of the water in the box, are a few water hyacinths. Very rarely do I clean the filter in the bottom and every once in a blue moon, I dunk one of the media bags in a bucket of pond water to rinse. That way, I don't kill the bacteria that has built up to clean the water.

So far, **crossing fingers**, I haven't had any problems and the water is very clear. All weekly tests have tested very good as far as nitrates and such. Hope that helps.

Coarse media in the skimmer basin, clean every few days along with the leaf basket. (In the early spring and late autumn, everyday, sometimes twice a day if you have a lot of leaf / granola happening).

The Savio skimmer came with a media (arc frame with coarse filter, about an inch or two thick). I need to replace mine because it is getting worn/soft but it really works at picking up clumping mud-like (detritus).

The Pondmaster pumps, I've read that too... But my Laguna waterfall pumps are mag-drive pumps and I purchased them online (can't remember where, it was an online pet store) for a great price, less than $100 each.

Beneficial Bacteria: I've always tried different things; of course, many will tell you that you don't need anything... but my experience is that our cool, stormy Kansas springs are slow at bringing the BB around naturally. So I seed the pond and the biofilter (not to be confused w/ the skimmer filter) with BB from Crystal Clear. Lately, I've tried another product All 'n One (not so temperature dependent). Last year I used Clarity Max and Clarifier by Crystal Clear, great but $$$.

By late spring last year my former tea colored water coming out of winter became amazingly clear.

The latest thing in BB are bacteria's that are not temperature sensitive... you can use them close to year 'round... so I've tried All 'N One this year and Crystal Clear makes a new competing product called One Fix. Seems to be helping. We've had a cool spring with few plants growing well but the water is clearing nicely.

I like Savio Springflo media in the biofall's box though like most media of this type it's expensive... Hardin's idea of scrubber pads is interesting... but Springflo truly made difference last year for me. In about five days the pond changed for me. I'm reusing it this year (link below). I don't have any experience with bioballs. I received Springflo below retail from a fella named Nate at Practical Garden Ponds.com. I think it was half of what the local pond store requested.

Nate says that he can only advertise it a the lowest price acceptable from the supplier... but he can sell it to you for even less if you request it for less. Interesting little game.

Like Hardin, I do water hyacinths as a supplemental filter. I don't think WH look wonderful or anything. I grow them for a natural filter. They didn't grow too well the first year of my pond but I listened to drh1, a chemist here on gardenweb, and I added a potassium nitrate fertilizer (no phosphorous)... actually, sold as stump remover, like tree stump remover at the lawn & garden centers... you'll have to check the product data sheets as not all stump removers are the same chemical makeup; you want pure potassium nitrate... the brand I found locally was Gordon's.

The Gordon's stuff worked wonders for producing huge roots to the water hyacinths... and the WH multiplied and multiplied, I gave and threw them away all summer.

Actually, WH can be coaxed a little... they're great for filtration but I used an upper pool on my pond as my WH filter pool. My lower pool after the waterfall was my water lily pool. Every so often pull the WH and crack off the adjoining sister plants, pulling it out of the pond quickly, rinse the hairy roots with a water nozel (lots of detritus collecting in them), and if you like, give the bottom third an upside-down haircut with a scissors. It really works well.

BTW, the ratio of stump remover to water for a pond my size was a teaspoon a week... I have lots of fertilizer left over for this year.

Okay, sorry to ramble... I'm sure you are going to do just fine. Sounds like you already had a solid grasp of everything.

Good Luck!