newbie looking for filter backwash disposal solutions

[psudds]

Hi everyone,

I and my wife are in the process of installing a formal fish/garden pond right now, with the help of a local contractor. Forms are going up as I write this, but the next big step is trenching and running plumbing, electric, waste lines etc.

We hope to be able to use the nutrient rich effluent from the filter rinsing process to irrigate roses, trees, and herb garden. The trouble is by our best calculations, the filter's rinsing process will produce about 200 to 450 gallons of waste water in about 1 1/2 to 2 1/2 minutes. Obviously, I can't exclusively rely on watering my little plants with a garden hose to dispose of all that yummy water, I'd be blasting a jet of water that bould blast my basil into the next county. We need some system that will allow both gentle watering and a high volume flow.

General suggestions are welcomed, but I'm really looking for anyone who has direct firsthand knowledge of how to accomplish this.

Here are the particulars of our (almost fully) planned system, for those who love/require the details:

Water Volume of System: approx. 2200 gal. US
Pump: Sequence Primer 8100 (8100 nominal GPH)
Filter: Aqua Ultraviolet Ultima 4000 (for ponds 2000 - 4000 gallons)
Fish Load: Light; Probably 10 - 20 inexpensive goldfish that will likely grow to no more than five inches (the bigger they get the fewer there will be)
Plant load: Medium(?) we expect eventually to have about 40-50% surface coverage with lilies and some submerged plants as well. There will also be deciduous plantings neatby that we expect to shed into the water.
Household wastewater is handled by a septic tank, no sewer.
Groundwater/runoff flows to nearby lake (Clear Lake, CA) which already has algal issues.
Landscape is pretty sloped, varying from 10 to 30 degrees (house is downhill from back yard, where most of the planting/irrigating will be).
Plantings to be irrigated are spread over a 75' x 35' area, with two small concentrated herb/vegetable garden areas.

200 to 450 gallons of waste water seemes like a lot to me, especially if it has to be dealt with in such a short time, but I'm pretty sure this is accurate. The filter's backwash/rinse process is described in it's instructional video as "backwash for 30 seconds, rinse for 30 sec, backwash for 30 seconds, rinse for 30 sec, backwash for 30 seconds, rinse until clear." Each rinse stage produces waste water to be dealt with, or 30 seconds, plus 30 seconds, plus (?) seconds. I estimated 30 to 120 seconds for the final rinse, so 90 to 180 seconds. Since the backwash and rinse process relys on turbulence to stir up the filter media and a swift rinse while the organic matter is still in suspension (before it's all settled out again) I presume the pump flow can't be necked down, so those rinses are running at 8100 GPH (2.25 Gal/Sec) for 90 to 180 seconds. Thus 202.5 to 405 gallons in three thirty second (or more) bursts. (even if I used a pump half this size, I'd still be generating over a gallon per second of waste water)

I double checked this calculation with the filter sales rep's estimation that the rinse proces will use 1/8 to 1/5 of the system's full volume, or 275 to 440 gallons.


Help anyone?

 

[sissy]

why would a filter have to rinse that much water through it .That means every time it rinses you will have to refill the pond and if you have city water that could be a real chore .That is a lot of water you would have to treat before it goes into the pond so you don't kill your fish .Oh sorry welcome .Sounds more like a pool filter would do to rinse it out and not sure it would even use that much water to rinse it out .Not sure what that filter is since i make my own but maybe someone here knows if that is right .

 

[psudds]

why would a filter have to rinse that much water through it .That means every time it rinses you will have to refill the pond and if you have city water that could be a real chore .That is a lot of water you would have to treat before it goes into the pond so you don't kill your fish .

Sissy,
Thanks for the swift reply. I'm just going based on the recommended filter for the pond volume and the recommended filter flushing process, and that's how the numbers work out. Seems like a lot to me too. We are going a little oversized on the pump and filter, because almost everyone we've talked with has said it's better to go oversized and neck it back than be undersized.

 

[sissy]

thing is that to refill that much water if you are not on well water may be a problem .How often does it say it should be back flushed .It may be a real problem for the fish also .Even goldfish may stress out .My yard is sloped also and if that much water comes out at one time it could wash all your nutrient rich soil away .I use the water from my pond for my plants also .I have koi ,fancy tails and fantaill goldfish also

 

[fishin4cars]

Is this a bead filter for mechanical filtration? If so that does sound about right. But 220 gallons is only about 10% water change so it's calling for a 10%-20% water change. That's about right for a Koi pond but on the high side for a water garden. But then my concern would be, what's doing the actual biological filtration? That much rinsing is going to remove a good bit of any bio-mass that would build up in the system I would think. If the total pond capacity is 2200 gallons the actual turn over should be between 2200 and 6600 gallons per hour. If your pumping up hill or to a long passage you will lose some flow rate there. But turning over the complete pond at 4 times a hour is a good bit of overkill. The best water for the plants would be the first backwash, that's where the nutrients for the plants will be. The rest is just water for the most part. It could be diverted back to the lake or drainage system. You could possibly pump the water to a higher holding tank and then let it gravity feed back to a irrigation system You may want to look at rain water collection systems and see if there is something there that will work. I'm thinking on the lines of two systems, one to catch the waste water to go to the plants, one to catch the rain water to help with the water bill for the pond.,

 

[psudds]

Hi fishin4cars (Larkin)

Is this a bead filter for mechanical filtration? If so that does sound about right. But 220 gallons is only about 10% water change so it's calling for a 10%-20% water change. That's about right for a Koi pond but on the high side for a water garden. But then my concern would be, what's doing the actual biological filtration?

They extrude their own three chambered ridged tube. Here's info from the filter manufacturer's website:


Bead filters use raw pellets
Bead filter manufactures just take these inexpensive pellets and load them into a filter body as is. The wax based plastic and smooth shape encourages clumping which is an inherent problem in bead filters. Some bead filter owners have been forced to backwash every day to prevent this clumping. When the beads stick together, water and waste pass around the large mass making much of the beads surface inaccessible. This allows untreated ammonia and solids to pass right through and return to the pond.
Ultima Media is specifically designed to support aquatic life
Using non wax based plastic Aqua Ultraviolet extrudes a patented media with the highest surface area of any on the market. The small tubular design has ridges on the outside and a cross section on the inside increasing bio surface area and preventing clumping. The ridged design helps to create a dense bed for superior trapping of solids that is easily separated during the backwash.
How can the Ultima II filters be smaller than bead filters and handle more fish
The Ultima II patented media design has 800 cubic feet of surface area per square foot. This is the highest surface area of any product on the market. The high surface area means less volume of media is needed so the filter itself can be smaller.

 

[j.w]

psudds
I like the idea of running the waste water into a holding container for your plants and using that w/ some kind of irrigation system so as not to blast your plants to the moon!

 

[psudds]

Cissy and Fishin4Cars (and anyone else nice enough to add their replies),

It's looking to me like I should have just said "Hello" in this subforum and put my technical question in the "Pond Construction & Equipment" subforum.

I'm hereby closing this thread and reopening it there.

 

[fishin4cars]

I was going to try and merge the two, Lets just say hello here and welcome aboard! Will try and help on the other thread.

 

[addy1]

Glad you joined!

 

[DrCase]

Welcome to the forum !!
A holding tank and a 2nd pump to water with , when your plants need it

 

[carolinaguy]

We use a plastic discharge tube for swimming pools. It's flexible, 50 feet long and has about a 2 inch diameter. Slow flow and it rolls up when you are not using it. I exhaust waste water from a 6300 gph external pump and the velocity is like a fast moving stream. It's about $50.

 

[Meyer Jordan]

5 year old thread.