Backyard Aquaponics
A place to discuss aquaponics

Gee, now i'm going to look light a right fool!

the inner pipe is 50mm

second is 90mm

outer is 100mm

i'll go back up and modify the previous posts, and you can remove the "WTF?" post VBV

Steve, isn't the hole through the tub 20mm or is it now 50mm all the way through???

Les, don't ask me what i was thinking yesterday! And no i don't do drugs

i've measured it agian 3 time to try and work out HOW i thought it was 20mm, especially since i use 20mm conduit so i know how big it it

Just quietly (ironic on an open forum) i think in my excitement of speaking to you on the phone i may have confused myself. Hmmmm 50mm is approx 2inches.............yep, that 2 looks pretty familiar on the tape measure. LOL what a goose

Anyway, GF's got the bloody camera again, so here are some dimensions.

INNER: 50mm diameter, 175mm long

SECOND: 90mm diameter, 230mm long, four 30mmx30mm crella-whats-its

OUTER: 100mm diameter with LOTS of 3mm wide drainage slots (i love my angle grinder )

So you don't want to borrow the chain saw
- 1st attempt I tried with a router (bad move)
- settled for 2 holes at each end then out with the jigsaw
- files to beautify for forum shots

When the 50mm is joined either side of the "plug hole", is the diameter reduced (do you still have the child finger catching grids still in place?)

I am surprised you are getting enough water into the 100mm pipe to feed the syphon once it gets going Steve - regardless of how many slits you have put in it. Though, you are not using gravel are you - u r using hydroton. This will drain much easier because it will not block the slits as much as a smallish gravel.

VB, phew! lucky i read this post before popping out to bunnings!

I'm just about to go buy some gravel........ its sunday, so not too many places open i'll relace the 100m outer with something larger...i'm sure i have some here! Yep, here it is, how about 160mm OD storm water PVC
I've just pulled my complete grow bed down! Was fun to see the "inner world" of the grow bed, more on that later.

Les, fingy gill removed

50mm home inside bath, 50mm male threaded pvc under bath, 50mm elbow screwed into this then a 3 meter run back to the fish tank in 50mm.

will work with straight horizontal outlet and with an elbow facing down.

if elbow faces up, i need to weight the center tube down with something to stop it floating, the bed floods slightly higher and then destinct "burps" and it syphons.

reduced the outlet to 20 mm conduit stub and syphon would not initiate......level just keept rising.

3m horizonal 50mm run is either level or on a positive incline by a degree. but definatly not ojn a negative slope.

have fun You're going to replicate this, aren't you LOL

That stuffed that theory - was thinking of a reduction at the plug point causing the siphon to work.

What is the water flow lph approx
What surface area is the tub approx
What is the height difference between stand pipe and siphon pipe
Do you have a large volume outflow, the 50mm pipe really gushing out
Is the end of the elbow clear of the water in the tank
What are the dimensions of the cutouts on the siphon pipe

Les, talk to me in inner middle and outer pipe, just so i don't get confused

can't tell you LPH on the spot as i'd have to measure it to be any where near accurate.

tub is 1.3m long x 0.6m wide

INNER: 50mm diameter, 175mm long

SECOND: 90mm diameter, 230mm long, four 30mmx30mm crella-whats-its

OUTER: 100mm diameter with LOTS of 3mm wide drainage slots

If the syphon pipe is the second pipe then 4 off 30mmx30mm cut outs

When she start man does she flow!

drain cycle is about 45 seconds
flood cycle is about 4 minutes

yept drain point is completely clear of tank water.

Sorry, GF's still not back, we might need a second camera

Steve -what have you done
you have just utterly destroyed all the auto siphon theory


So the gap between the top of the inner pipe to the top of the middle pipe is 55mm - how high does the water rise before the siphon kicks in, does get to or above the level of the end cap on middle pipe

lph not required

ROFLMAO!

Actualyy i've done this before to theories. SORRY

Nope level does NOT go above sealed 90mm pipe.

I've just been playing with the bed epty of gravel, it did not want to kick in. I think that its not so much the LPH into the bed, but the LPH RELATIVE to the surface area:volume! The water level rose MUCH slower with no gravel in itand the rate of rise of the level was not enough to initiate the syphon. But i suspect that you know this.

I have also changed my outer pipe to 165mm as with the bed empty i realised that the syphon cut off becasue water was too slow in reacing the inside of the outer pipe due to the slits.

I have used the 165mm pipe and cut as many slits as i can (ALTO!) but it still suffers from this to some extent, not too bad, really, but i want to get this as good as i can before i fill it with blue chip gravel tomorrow morning.

What i am about to do is cut 20mm holes in the first 2 inches of the outer pipe, and pack the outer pipe with white ornamental pnd rocks from bunnings.

i believe this will solve the problem with out passing gravel into the tank.

The reason it suffer more from this problem as the bed empties is that there are progressivly LESS "parralel" water paths through the outer pipe as the level drops.

off to bunnings.

Steve

agree that's why I wanted the surface area to work out minimum inflow to GB - well actually its the rate of rise of the water, it will rise quicker with medium than without

Tested the height difference theory between inner and middle pipe, I raised mine from 10mm to 50mm and siphon still worked okay - water level DID NOT rise any higher though on either setting

Agree with parallel water flow required, especially on 40 & 50mm pipes, that's why I started experimenting with the small plastic baskets to use as a false flooring method

Still can't understand how YOUR siphon works with so large a pipe without dunking the end and restrict air flow into the pipes YET

just a quick approximation of your inflow:

GB = 1300*600*300 = 235 litres / 2 (because of medium = 120 litres of water)
120 @ 4 minutes = 1,800lph (or there abouts)

you are syphon king

just waiting for GMC battery to charge, bought a bag of scoria for $8

am drilling about 6 16mm holes around base of outer pipe to hopefully increse low end water flow. If it doesn't work then thats cool, i'm still happy enough

Les, do you think that the 3 meter LEVEL run is the reason behind my "non-conforming-newage syphon"

When i "look down the barrel" i can see the water level rising until it fills the pipe, then GUSH.

I think the auto-break function may be due to the crells being just that little bit bigger?

Steve