Backyard Aquaponics
A place to discuss aquaponics

The other thing I am having problems with is the Grow bed fill rates. They all fill at different speeds and are very sensitive to how high they are. It would be awesome if I could get the pipes underground and then just have the pipes pop up next to the gb and bend over to do the filling with some sort of method for adjusting the height in order to control the fill rate. I thought if I come up with pvc and bend over 90 deg and then use a piece of black flexible pipe with a 90 degree bend down. Then I can just wedge the pipe at the correct height to get the two beds to fill at the same speed. Or I can just set them level with a water level or something or leave the ends loose and get the speeds right and then glue them or . The pipes lying across the top of the GB's are annoying cause you need to step over them all the time. They are messing with my fung shui! Any advice appreciated!

Nice sunset.

I like the idea of regulating flow to the beds an elbow on each outlet in each bed so one can swivel them to raise or lower the flow. Level will not necessarily do the trick as distance and other troubles will affect flow.

If you wanted to eliminate above-ground FT>GB plumbing lines you could run the 50mm out to a T right outside the FT. Leave the top end open to avoid air locks and drop a 50mm tube down to a larger manifold pipe (75mm?) that runs underground. Then pop up from that as needed for the growbeds. I strongly advise having some way to wash out the manifold as sediment will build up: leave access so you can run water from the sump pump into it and wash it out if it ever becomes obstructed at all.

Yep, you can run pipe down to the ground and pop up for each grow bed. Do remember that the longer the pipe and the more bends you have, the slower water moves through them. Also, having a clean out somewhere along the line is a good idea too.

Balancing flow into grow beds can be challenging. As for a method of adjusting the height, you might look into compression fittings that can give you several inches of play between the ends of the pipe for the rise and then a couple elbows and a couple little bits of pipe might do it. I would make the height at the near grow bed a bit higher and lower as you move away but it will all kinda depend on how your water is trying to flow.

Just plumb a ball-valve into each growbed outlet... and adjust accordingly...

I use these. I don't know what they are worth as they were just a part of the $100K or so bill for the drippers. They are the flushers that go on the end of the dripline. I have a whole box of these because the batch we got to begin with leaked and all 400 or so were replaced, but the leak doesn't matter for the AP because they are never off. If you lived in this SA, you could drop by and grab a couple .

Thanks for all the advice guys. I was counting up how many t's and elbows and ball valves I would need to get everything plumbed underground and the added issue of keeping them flushed and it is quite a bit of extra missioning just so it looks better so I am going to leave it for another day when I have got nothing better to do. I managed to get the third grow bed filled up today. I had ordered a half load of stone from the truck guy who delivers and when it came it looked a bit mingy. it was supposed to be 2.75 cubes and it only managed to fill two grow beds of 1 cube each so I went and moaned today and he chucked another scoop on the back of my truck at no charge .

When we got back I had a brain wave for washing gravel and it was definitely the best method that I tried so far. I parked the quad bike with the trailer facing the back of the truck, kind of back to back. Then I had a fine compost sieve between the truck and the trailer. I got one guy to shovel gravel onto the sieve while I poured copious qty water over it while another guy moved it up and down the slightly angled sieve. when the water ran clean we moved it to the trailer and just kept on going. Worked very well .

I managed to get some pure ammonia 25% solution. Strong smelling stuff. I have no idea how much to add to the water. I chucked in a cap full 25ml today, and will test tomorrow to see what has happened.


Ran some tests before though

sorry for posting that Ph 3 times... looks to be around 8.
The other is the ammo still low at around 0.1 to 0.3 ppm
Here is the Nitrate which seems to have gone up


looks to be around 50 mg/L

I also had another problem with pumping today. The bypass valve that I put in to slow down the fill rate had a fairly long piece going into the sump and it managed to siphon all the water from the pump so it did not pump. I cut it really short and it seems to have stopped the problem although technically it is still lower than the pump and plumbing. Perhapse I should raise its output to higher than the pumps height

I just realized that you guys always talk of ppm but my test kits are in mg/liter. How does mg/l relate to PPM. . How many mg in 1 liter... google...

1 000 000! Duh

The cap full of ammonia seems to have made no change to ammo readings. I am going to do some maths to work out how much ammonia to add. The guy at the fish shop advised I take out the check valve and do this instead.


The pipe comes up above the level of the FT water and then a small pipe is drilled into the pipe at the top with a 45 deg cut facing away from the flow. This acts as a venturi when the water is flowing and a siphon break when it is not. The venturi helps aerate the water. Has anyone tried this? I checked locally for a pvc check valve and the price is insane! R1200.00 (about $190.00)

$190 for a check valve? That sounds a lot. You might be able to buy a pond (submersible) pump for that and all your problems would go away, including the one where your pump cavitates because of the aerated water. I'm not sure of any of these remarks.

Found cheaper check valve- all pvc with ball valve and stainless spring. About $10 and $10 for shipping. So that is sorted . I just needed it yesterday! I calculated I would need to chuck in 140ml of 25% ammonia to get 7000 liters from 0 ammo to 2 ppm so I figured with the pee and all i would chuck in 80ml for starters. Now the ammo reads 1.5 ppm so I am getting there. I will check tomorrow and then add a little at a time till it is 2 ppm. Plants are looking perky although the lettuce needs shade.

I have gathered together several 50mm heavy steel pipes from around the farm and there is quite a bit. About 16M or so. I am thinking to weld them all together and form a really strong kind of central spine for the tunnel and use that to hang the PVC pipe hoops on. The hoops can get concrete blocks on the ends that will hold them in place. It would also be very usefull for hanging a nft pipe from.

Amonia now at 2.4 and nitrate at 50 heading to 110.... jikes... what to do? leave it alone I guess...

Yep, now is time to leave it alone.

Keep testing the ammonia and pH and see if you can get a nitrite test kit. (perhaps mail order?)

Nitrates can go quite high without any problems. Mine are usually quite high (probably due to my high pH slowing the plant's use of them because other nutrients are less available at the higher pH.)

So was it the bypass that caused the siphon or was it the main pump intake that siphoned the pump back out? If it was the bypass, just make sure the pipe dishcarges above the water line and hopefully above the height of the pump.

If it was the intake pipe, hum......
If you can find a swing check valve, it will restrict the pump intake less but they can still get wedged by debris and not stop the backflow but between it and a priming pot, you can probably keep the system running. However, my use of a non/self priming pump above the water line is the reason that my big system pump is set up for continuous running and until I got my hands on an indexing valve, my system ran with siphons. My pump is very energy efficient. I would be using a submersible if it wasn't for the fact that my pump is so quiet and energy efficient. (The original pool pump I had gotten for free to run my system was not energy efficient and used about 10 times the energy of my current pump.) If your current pump is not energy efficient, I would urge you to simply get a good submersible energy efficient pump to run your system and do away with all the headachs of the check valves, priming pots and worries that the pump might loose it's prime during any of the many pump cycles per day.

2ppm=2ml(pure ammonia)/kl=14ml/7kl
Since it is 25% ammonia you will need 4x as much or roughly 60ml....
So 80ml would bring your system to 80/60*2ppm=2.7ppm and 140 would give you 140/60*2=4.7ppm.

Umm....I think limiting it to 80ml was a good idea...although I have read an old study that found the fastest cycling rate took place at 5ppm.

Hey, I misplaced a decimal and almost added 30ppm salt to my system once!