chop system design questions

[glenn wilkerson]

how much higher should my fish tank water level be than my grow beds stand pipe. I figure about 6 inches so that i can use a 2 inch over flow line and have a little pressure i the line.

[Aquamaple]

TCLynx said:

What do you mean outlet to SLO ratio? 

So perhaps you branch off your 3" SLO with some 1" lines to feed your grow beds...

My apologies. I meant, how do I determine the size of the piping for the branches off the SLO to the grow beds? As you mentioned, too small of pipe will leave an excess of water in the end of the SLO pipe, while too large output branching may reduce water flow to nothing by the time the final bed is reached. Before, I had not remembered the possibility of putting valves on the outputs, which would prevent the situation I just described. In your experience, do half-closed ball valves at the grow beds cause a point of much bio slime that would clog faster than the rest of typical plumbing? If not, it seems it would be advantageous to over-engineer and simply restrict with ball valves at the grow beds. Thank you for your patience and help!

[TCLynx]

I hope you noticed the diagram I put up showing how one might use an elevated bit of the pipe at the end (but still lower than the outlet from the fish thank) to make sure you don't restrict the flow too much but still have pressure to the other beds.  This bit is actually hand since if your smaller pipes or ball valves do get clogged at least there is a path for the water to go rather than overflowing the fish tank.

Ball valves closed part way will regularly build up clots of fish poo/bio-slime but it's usually easy to clear by opening then re-setting the valve once clear.  However since ball valves cost, I've been known to simply use a uniseal from the larger pipe into like 1" pipe and having some elbows and bits of pipe to adjust the height of each outlet a bit to balance them.  Just call it PLART  What happens when the stray plumbing bits from the bin just get slapped together however they are to get the desired effect without cutting or buying new pieces.

Ya just got to make sure there is an unrestricted path out of the pipe after the SLO and that end bed or where ever you let that unrestricted pipe flow to probably doesn't get to be a siphon bed since it may be nearly impossible to keep the flow there perfectly balanced for the siphon.  (Constant flood works too.)

[TCLynx]

yep, they just come up to the interface between the flooded and top layers if the water isn't aerated enough for them.  but in aquaponics, I've had worms surviving totally submerged in the sump and the pump basket even since I keep my water well aerated and I tend to have way more flow than the minimum recommendation.

[TCLynx]

If the flow slows down enough to leave the siphon only trickling over and not kicking in then at least the media won't dry out and kill the bacteria.  If it fails drained and the flow is too fast and the siphon doesn't stop, then you risk drying out much of your media and the bacteria living in it.  The worms will generally move where they need to.

[Aquamaple]

For starters, my system will be little more than one IBC FT, one IBC sump, and 2-4 GB's. At this point I am intending to use a pump with 1" inlet/outlets with 16gpm (960gph) at about 50% on the performance curve (at 8ft head). I don't expect any more than 4 or 5ft of head. I will divert some water back through a 1" spray bar, with some small holes for aeration.

I did see your diagram, thank you! Uniseals for 3" pipe, uniseals or adaptors for 1" pipe to the growbeds, with the upturned pipe just like in your diagram for my SLO. I will be using auto siphons for all the grow beds if possible, maybe constant flood for the last one. maybe. I will have minimum and maximum limit switches in the sump for the pump. I will also have backup overflow outlets in both the sump and FT.

I have two more questions. 1. Is it only necessary for one point of water going into the GB, or should there be more? I will be using IBC's for grow beds. 2. What is the best way to keep fish out of the SLO without restricting flow?

TCLynx said:

Uh, Mark, I need to know more about the size/scale and flow rate (pump size and head) of the system in order to make an intelligent recommendation.

 

[TCLynx]

I've used those Artium Grates on the top and bottom of my SLO drains with either a stainless steel screw or ziptie through a hole to keep them from being knocked off but still removable for cleaning when needed.  You can probably also fine appropriately sized net or slit pots for the purpose as well.  Make sure the grate is open enough to allow free flow of water even with a bit of clogging or you may see overflow issues.

I usually just flow water into one point in the grow beds but other people use distrobution grids.  You can probably always add a distrobution grid later.  Just make sure there is free flow out at the last bed so you don't risk backing up your SLO when the holes start getting clogged up.

[Rob Jordan]

I am building almost exactly the same system as the diagram by TCLynx below, except I only have two GB. Tote system with 300 gal FT, 100 gal buried sump. My pump is plenty large at 1500 gph with 1 1/4" output. I'm only lifting about 5'. I understand the output side, but have a question about drainage pipe sizes. How big are pipes coming out of GB siphons to sump? I understand the concept of the SLO drain from the FT, but how big is the vertical, horizontal, and downspout? I was planning to use 2" for SLO, but now think I should go 3". Any advice?

[TCLynx]

I generally do 3" SLO drains on IBC fish tanks but I use uniseals so the fittings are pretty reasonable.  You can always downsize later with a few bushings if you need to.

For siphons I would probably do I" drains on the grow beds and then have the drains from the individual grow beds feed into a shared 3" drain pipe.  A trick I learned if you want to be able to pull the stand pipes out of a bed that you use uniseals to plumb, you use a 1 1/4" uniseal and put a 1" coupler into it, now this won't work if you can't accept a small drip since the 1" coupler is a hair smaller than the 1 1/4" pipe but most of the beds I've done that with have the drain hole positioned such that any small drips land in the sump tank or into the larger drain pipe below the bed so it hasn't been a problem for me.  This trick may also work with 1" uniseals and 3/4" couplers, 2" uniseals and 1 1/2" couplers.  Just make sure that the little nub from the molding process isn't in the uniseal or you may see more leakage around that too.

Anyway back to drain size for an IBC bed a 1" drain works and you can always use a bushing to adapt down to 1/2" for the affnan modification for the bell siphon.

I have some IBC beds with 1 1/4" drains but they are timed flood and drain with an indexing valve.  I have larger beds with 1 1/2" drains and I'm using 1" stand pipe drains on the two rail beds I'm running with siphons, I've not bothered with the affnan modification on those since they pretty much just worked as they were so I left well enough alone.

For the 3" drain pipes I usually use the 3" sewer and drain pipe since it is less expensive.  Trick I leaned is that the outside of those fittings will fit inside of the regular 3" PVC fittings so you can avoid the extra adapters and I've leaned I can actually use the 3" sewer and drain coupler pushed into the 3" uniseal so it makes it easy to pop the SLO drain assembly in/out of the fish tank.  I usually add a little stainless steel screw to keep the fish from knocking the pipes apart in the fish tank instead of gluing all of them.

For larger systems I'll go up to 4" pipe.  I've never built a system big enough to make me want to use 6" pipe yet though.

[Moe]

Hi,

How do you figure your pipes to suck air and water together?

Thanks

Harold Sukhbir said:

Hi Glenn,

You're only limited by your pump lifting capacity. To be safe, keep up to or below the 80% lifting range of your pump             ( Between the sump and FT). Personally, I like to go to near the maximum lift because i configure my piping to suck air and water together, giving the system extra aeration. I also like more flow-rate and higher water pressure(by using gravity) to help minimize bio slime buildup in the pipe runs.

[Harold Sukhbir]

Hi Moe,

Google Aquaponics Venturi

Moe said:

Hi,

How do you figure your pipes to suck air and water together?

Thanks

Harold Sukhbir said:

Hi Glenn,

You're only limited by your pump lifting capacity. To be safe, keep up to or below the 80% lifting range of your pump             ( Between the sump and FT). Personally, I like to go to near the maximum lift because i configure my piping to suck air and water together, giving the system extra aeration. I also like more flow-rate and higher water pressure(by using gravity) to help minimize bio slime buildup in the pipe runs.