some basic questions

[Pat James]

I presently am using a vertical hydroponic system in my greenhouse. I have a fairly large swimming pool that I plan to use as an aquaponics system.

I live in northern Louisiana, so I will probably wind up with catfish in the pool. In the interim, I am going to put in some rosy reds which are really a red color variation of fat-head minnows. they are supposed to be omnivorous so maybe they will eat up some of the  algae/leaves/crap that has accumulated in the pool. The catfish can eat them later...

I have been doing my reading, but still see alot of conflicting advice. I know I need to bypass the existing sand filter and that is not a problem.  I have a fairly large pump for the pool (20k gallons or so)..about  1 1/2 horse pump. I have no idea of the gallon/hr but I know it is big. It powers several jets into the pool with a VERY powerful flow.

What I was thinking of doing was cutting the existing lines and redirecting the flow into a large plastic barrel sitting on top of the diving board platform.

I thought of putting taps into the barrel at some point lower than the top  to feed the plant beds by gravity. i would have an overflow at the top of the barrel that would fall directly back into the pool. That way I would not have to worry about excess water flow.

I have planned planting beds on both sides of the pool along the deck. I think a simple ball valve will let me control water flow to each side of the pool for the beds. One side is far larger than the other.

Now for the questions...1. I have seen people talk about the necessity of a biological filter before the plant beds to allow for the nitrifying bacteria. Is that really needed, or do the planting beds themselves suffice?

2. As far as the plant growing beds go I am looking for the least expensive option.  For my present grow beds, I am using 4 inch sewer pipe with 1 inch holes spaced at 8 inch intervals staggered on 3 sides of the tube.  (Remember these are vertical). What are more economical options?

3. For the aquaponic system I was thinking about using similar pipe with connections that would direct the water flow into the first pipe and then in a zig-zag  pattern through the whole bed. then back to the pool. i think setting up mini bell siphons in each run (about 25 ft long) would be problematic....so...

4.Is an ebb and flow system that much more beneficial for plants than a continuous flow or NFT system?

5. i can always add fresh water to the pool and, by adding a tap to the barrel on the diving board, have a gravity fed source of water to run to my regular garden beds. i figure this will allow me to adjust for  for at least increased ammonia levels in the pool.

I welcome all comments and criticisms. I was trained years ago to think through a project to identify all the things that could go wrong and then correct them ahead of actually trying it.  However, this is all new to me.so I am doing this intuitively.

[Chris Carr]

Not sure if I have seen anyone else here mount the blue barrels like Jon does. Minimal material needed and no issue about them bowing or rolling around as they are securely hanging from the support. Not sure why most wouldn't want to do this. I guess it is easy to be skeptical that the holes in the plastic wouldn't hold the weight of heavier media but seeing is believing. I really dig it.

Jon Parr said:

I let the earth support the troughs, and stakes and 2x4 rails to support the sides, no plywood. For media beds, I use free blue barrels gun-nailed into 2x4 rim frame on posts, again no plywood, cheap cheap.

[jim mckee]

Why remove the pools sand filter? (ironicaly I'm shopping for a small one)

I'd run it on the side to clean the tank and its water.

You can also tap into it and provide flow for grow beds but you will have to feed a big motor and you will have enough pressure and flow to run your system and 2 neighbors grow beds .

I didn't catch what the pool is made of, if it's crete I'd spring for good sealant/paint from the beginning (that lets you clean the pool also).

jim

 

[Jon Parr]

Chris, I find no fault with the blue barrels split lengthwise and nailed. I use full-head weatherized nails, and they are above the water line. The barrels are thick plastic, and there is no sign of it stretching from full beds of granite. I've been using that style for three years, and I've not seen anyone else do it my way. Usually they set them on the ground, or on a support, and block them from rolling. Then the sides bow and it looks terrible. To each his own.

Jim, I believe the pool is concrete and plaster. Hey, did you ever build the gasifier? I did, and now need to pull it out of hiding and fire it up.

[jim mckee]

Ah crete/plaster so hopefully he will have a chance to seal it.

I'm just about done with the gasifier.  I test ran it the other day.  The first thing off of it is a 40gl hot water heater tank submerged in a tank of water.  I'm using that hot water to feed a fan forced air heat exchanger in the green house (summer time the hot air goes outside).  Today I pull out the engine for the gasifier.  It's a 4cyl ford engine mounted on an Asplundh wood chipper and it has a bell housing with clutch takeoff to 3 pulley.

jim

[jim mckee]

Chris

I'm trying to find what you are refering to.  Do you happen to have a link or more info?

Thanks

jim

Chris said:

Not sure if I have seen anyone else here mount the blue barrels like Jon does. Minimal material needed and no issue about them bowing or rolling around as they are securely hanging from the support. Not sure why most wouldn't want to do this. I guess it is easy to be skeptical that the holes in the plastic wouldn't hold the weight of heavier media but seeing is believing. I really dig it.

Jon Parr said:

I let the earth support the troughs, and stakes and 2x4 rails to support the sides, no plywood. For media beds, I use free blue barrels gun-nailed into 2x4 rim frame on posts, again no plywood, cheap cheap.

[Rob Nash]

Pat, im a fan of "build you own" plywood boxes... 4x8 is the best because there is no waste, and if you use the pond liner from Home depot, the large piece (13"x20" $96) does 4 beds. just use the 3/4" plywood with cinder blocks under it and your good to go. ..the real problem here is that your going to have to fill your yard with grow beds to filter that much water... you will need a crap load of fish (pun intended) and a much smaller pump. ...it takes about 250 sft of media bed to filter 1000 gallons.. how many gallons did you say the pool was? are you prepared to build and manage that many growbeds? remember it will take a lot of fish, a long time to get your water where you want it.

there are several ways to convert to an all natural swimming pool, and then you could keep your ap project smaller and more manageable.

 

[Pat James]

I'm finding the lumber prices to be in almost the "stupid" range. Rock is higher than I thought as well.  I found lava rock for $100 a yard, river pebble of unknown type for $60 a yard.  That is the pickup cost. I calculate I will need 6 1/2 yards to fill 48 barrel beds.

I was quoted $17 for each 55 gal food grade barrel. I'll try to negotiate a better price when the time comes. PVC pipe is fairly cheap but fittings are not and I will need to do alot of plumbing.

Channel cats seem to go for about $30/100, so that appears to be the cheapest component. I have no idea of feed costs.

Jim, I read that a sand filter is not advised in an aquaponic system because of the coarser (bigger particle) size of the sediments. That is plausible if you have ever maintained a pool. Even a fair amount of algae will cause the filter to quickly plug so  very frequent backflushing would be required. I'm not sure if my pool valve system can be used to selectively bypass the sand filter for routine use. If it can, I will have the ability choose those times I run the water through the sand and even retain the ability to drain the pool for water changes.

[Chris Carr]

Pat. You may try looking around for a factory or the like which may have waste food grade barrels you will have to clean out. It is likely that they are paying someone to take them away. Somehow people on craigslist are getting them for free (I assume) and the prices they charge are usually for cleaning them out and delivering them.

 

Jim, as Jon mentioned he is the only one he is aware of that uses them this way. You can sort of see a couple of them here on Jon's website above Glen Martinez's head under project #3 http://www.fishnetaquaponics.com/gallery.html

 

Just for kicks I scribbled them into mspaint. Its just the barrels in half lengthwise like everyone does, then frame the rim with 2x4s and fasten them from the inside into the frame. You can support this frame anyway youd like, posts, bricks, hung somehow, whatever. but the idea is the barrels are supported by suspension, not from the underside.  Image is not to scale and needs more nails/screws obviously, you get the idea.

 

[Jon Parr]

Sweet drawing, Chris. I'll make a vid and post it tomorrow (I always say that and seldom do it...)

Jim, congrats on the gasifier. I've been wondering if you had success.

Pat, like Rob said, it will take a lot of beds and fish to max the aquaponics potential of the pool, but I personally think it won't take much to max the pool potential of the aquaponics :)

[Pat James]

 jon..I was thinking the same thing.  Since my growbed potential is determined by space (and money starting up), I figure that the number of fish I start with as fingerlings may be too heavy a biological load as they grow. In that case I can add extraneous (non-grow-bed) filtration as needed.

[Vlad Jovanovic]

Hey Jon, couldn't Pat just stock the pool according to (his bio-filtration capacity) how much grow bed space he's able to come up with (380 sq. feet). I understand that he's not going to be able to turn the water volume of his tank (pool) over once an hour, but really...Doesn't that suggestion (which now seems to be carved in AP stone) come from intensive RAS anyways. (and hasn't it always been a 'suggestion' not necessarily a requirement? Yeah, I get that it's generally a good rule too follow and all...but hardly seems necessary in every single scenario, right)?

I'd be more worried that their might not be enough nutrients in solution if I stocked 20K gallons with enough fish for 380 sq. feet worth of GB's...but even that is hardly a tough hurdle to overcome...

Pat, if you make your GB's twice as deep, you'll get twice the bio-filtration capacity in the same square footage (footprint). Allowing you to stock more fish if you want or need to. People seem to tend to overstock their systems anyways for the amount of plants they want to grow IMO. 

Yeah, cool drawings Chris. (...and Jon, quit lyin' ya lazy bum! We've been waiting on new pics or vids for like a year now...

[Pat James]

If I go with the 1/2 barrel system that I think is what I wind up with, I think I will have a deeper than 12 inch system. Each bed should have about 3.5 cubic ft of filtration.

If I need to, I can add some extra filtration. Years ago, when I had a pet store there was alot of interest in what was called a 'wet/dry" system. Essentially water was sprayed across some media then fell through a space into another layer of media etc... I greatly enhanced the nitrification.process.

Back then, (early 90's) it was useful in salt-water aquariums where the fish were especially sensitive to ammonia levels.

I think in an aquaponics situation, you could simple fill a barrel with some big filter media...plastic pieces etc with a fair amount of surface area and then let the water spray over the surface. Bottom layers would NOT be submerged.... the drain would be large enough to make sure the media stayed well but drained completley.