Backyard Aquaponics
A place to discuss aquaponics

These are not isolated examples...

PLJ do you have growbeds on this beast of yours ? Plan to ?
What are your near term goals ?

No, SuperVeg, I don't have any growbeds. I have a bamboo raft floating in there with a few lettuces and silver beet fitted into it in a very rudimentary DWC attempt. I also have a lot of Azolla pinnata floating in the tank which I scoop out almost daily and use for poultry feed and as a green fertiliser. I am also experimenting with Azolla as a salad item and, frankly, it doesn't taste too bad - somewhat like Brahmi (Bacopa monnieri), which I am also planning to grow in a raft pot in the trout tank.
At this stage I don't plan to filter water from the tank through grow beds because I can't think of a suitable way of doing it. With an ammonia reading of around 0.2 ppm I believe I do need more filtration and am open to suggestion. I was thinking of making another 200litre drum biofilter to assist the one that is already in operation. It seems to be working really well but just doesn't filter enough water in relation to the whole system volume.

Haha, are you my high school guidance counsellor, SuperVeg?
In relation to my big concrete tank system my primary goal is to keep my Rainbow Trout alive, well, happy and growing until whenever I decide to harvest them later in the year.
Near term goals? I want to improve water movement and circulation to reduce the possibility of stratification in the tank. I want to increase the area of coverage of my solids drain pipe set-up. I want to take steps to increase the flow through my biofilter and then add a second one. I want to get some more plants established on rafts in the tank.
My planned IBC system has stalled, as has the blue drum system that I am supposed to be helping my son with. I suppose setting up each of these systems provides me with two more near term goals.
Why do I feel like I am laying on a therapist's couch?

haha sorry about that, it didnt feel like those sort of questions when I wrote them

I am just interested in such a system. It would be great to turn an old tank like that into a nice big system. I wonder if it would be easy to get a couple of IBC, fill them with gravel and use them as bio filters ? Pretty much grow beds then without the plants.

I didnt realise you could eat Azolla, I think it is a pest here, but not sure.
It is certainly easier to grow that for salad greens than setting up grow beds.

My son is just over 1 and im looking forward to his first system, might have to wait a few more years though

You passed the test

Same time next week, doctor?

Yes, this time next week and every week for the next 20 years.
Just take these pills, and these pills, and to stop the side effects from those pills, take these pills.
Oh, and don't forget to pay the $1200 on the way out

At least you will already have the expertise if and when he is ready, SuperVeg. Three of my adult children are interested in having their own AP systems and are after my help, as is the youngest one still at home, as mentioned. I also have a friend seeking guidance on the conversion of her 10,000litre pool to a FT. Bloody hell, I am barely managing to keep my own fish alive - and have yet to fashion a working grow bed - but my family see me as the *expert already! Such is the seductive power of the sound of running water and fat fish splashing in a tank at tucker time: who wouldn't want to have them?


* read X-spurt:
X = unknown quantity, spurt = a drip under pressure

I am thinking of connecting two 450-500litre grow beds (GBs) to my system to both increase the level of filtration and to make better use of the nitrates available in the fish water. I think I would need to pump/siphon water out over the side of the tank (rather than through the outlet at the bottom), circulate it through the GBs and then pump it back into the tank. I want to be able to do this with just one additional pump, preferably not on a 24/7 cycle.
I think I will also need a sump to handle at least the capacity of the GBs, ie 1000litres minimum. I can't envisage how a siphon will work in this situation since drawing off 1000litres from the FT will only lower the level about 24mm.
Someone else's input would be appreciated.

Try to syphon up and over the sides of your tank (no holes overflow) , flood grow beds constantly but regulated to as slow as you can either by ball valve or small hole(s) in distrubution pipe , drain to a sump , pump back to your tank with a float operated pump. You can get float switch's to control any pump via a 3 pin plug.
EB now dislikes sumps , sump pumps and float switch's

Cheers

Won't need to be a siphon can be an overflow at the height you want. The pipe can still go down to the bottom of the tank so water is coming from there.
Will mean drilling through the tank wall...

Why not just use the bottom outlet

That would work for me.

I understand and like this idea. Constant, regulated flow to the GBs simplifies the siphon situation. Using a pump with float switch (which I already have) sitting in a sump would work, and satisfies my preference for the pump to not be running fulltime. My main concern was not to set this up in a manner that could allow the tank to empty via out of control siphoning, for instance if the pump failed, since the GBs will be positioned much lower than the water level of the tank.
Thanks, Matthew.

I like the idea of an overflow but don't really want to drill holes in the tank, if I can avoid it.
If the pipe was to extend down to anywhere near the bottom of the tank, presumably to suck up solids, wouldn't it then take on more of a siphon function rather than an overflow? I would be concerned about losing anywhere up to 75,000litres of water through my GBs with no return, eg if a fitting separated or the sump pump failed. Perhaps I am not fully understanding you Privatteer.

If you wanted to have the water drawn from the bottom but limit the level it could siphon to, just drill a small hole in the side of the pipe at the level you want to limit it too. This will suck enough air to stop it.

NHO are prone to stop when ever they want due to getting air in them. What i did to over come this is have a small air trap at the highest point in the overflow and have a small 4mm siphon from there to suck out any air. Credit where credit is due, i think i first saw the idea from web4deb. The other thing i did to make it easier to bleed up is put 2 valves on wither side of it so i could close them, fill it up with a cup at the highest point and then just open the taps. This will also let you regulate the flow. I know that isnt a good description so check the first few pages of my aquarium to get a better idea.

I already use the bottom outlet of the tank for my solids drain. Water drains out of this outlet and up to my biofilter system and then is pumped back into the tank. The biofilter drums are elevated to match the level of the tank so that when the pump is turned off (or if it fails) the water finds its own level below the tops of the filter drums.
I don't plan to raise the GBs to this quite inconvenient level.

It is a good enough description for me to understand it, rsevs3, although I had to look up the abbreviation NHO. (Interestingly, it doesn't get a mention in the Glossary and I had to do a search on it.)
I wish I had been armed with this info back in April when I installed a large No Holes Overflow on my tank. Sadly, I didn't even come close to getting it to work!