Backyard Aquaponics
A place to discuss aquaponics

Gurkan & Dave,

Thanks for the info. Will keep everyone updated and post some pics when I get to start building. Hopefully in the next month.

I appreciate all the advice.

And yes Dave, it is rather cool in Jerrabombera (Canberra) today.

Just a quick note - you've been saying you want to do timed flood and drain with bell siphons. Errrr... pick one! They both serve the same purpose, to flood and drain your growbeds, but don't work together.

If you go timed flood and drain, you need a standpipe with a media guard but no bell, and a couple of little drain holes in its base. When the timer switches your pump on it will fill the growbed up to the height of the standpipe and then start overflowing down it; when the timer switches off the water will trickle out of the growbed slowly through the little drain holes.

If you use bell siphons, you need a standpipe with a media guard and bell, no drain holes. The pump stays on all the time, usually running with a lower flow rate than timed flood and drain needs; when the water has filled up your growbed and starts spilling over the top of the standpipe the siphon kicks in and drains it all out again, then the siphon breaks and it refills.

Basically timed F&D fills quickly and drains slowly; bell siphons fill slowly and drain quickly; both work great, it just depends on how you want to set things up!

Mel's post has me realising that the advice I gave earlier in this thread and also in a separate one didn't make the difference between the two clear enough.

You're probably aware that there's also constant flood. Much like the flood and drain described above but no hole in the bottom of the standpipe.

There are probably unwinnable arguments about which system is best... seems to me that they all work well but have differences in their reliability, perhaps power usage, and total water volume.

Total water volume may help with system stability (temperature and perhaps more generally).

It took me a while to tune my bell syphon properly but reliability hasn't been an issue since I took Mr Damage's design advice - well worth searching for relevant posts if you do go with a bell syphon. I like having a bell syphon in my original growbed because I still get a tiny little kick out of the wonders of hydraulics every time it makes and breaks. But my constant flood growbed's plants are just as healthy.

As long as you don't glue your standpipe in, and have a big enough media guard to allow a bell syphon to fit over the standpipe, it's easy to change your setup if you change your mind down the track.

I'm a newbie here so don't take this for gospel but your sketch has me concerned about the pump location and having multiple connections between fish tanks to keep them at the same level I'm assuming... I'll let the other guys that know more comment if I'm wrong, but wouldn't it be better to keep the fish tank at a constant level and only have one connection (or multiple connections but all at similar heights) to the sump tank (yabbie tank), then pump from the yabbies tank? This is the concept of CHIFT-PIST right? Just seems less hazardous to me, what if you get a leak someplace it's only the yabbie tank that risks lowering not both tanks (and yabbies would probably still be fine because they are able to live out of water for a while, but would likely still have an inch or two of water in the tank assuming the pump wouldn't be able to suck it dry).

In that case I'd have the grow beds flow back to the fish tank, then the fish tank can SLO drain to the sump/yabbie tank.

If you are planning on flood/drain that would mean both your fish tank and your yabbie tank would constantly be changing their water level... so at the lowest water level your fish are going to be pretty crowded, then when the GB's drain the fish will have more water for a while until it floods again... seems like a constant cycle of stress for the fish to me...

Rininger85,

...I am just as green as you regarding AP, but I am following since a few years now and "my plan" is still changing constantly - though now it is more about fine-tuning the "dream system".

As I see it - .....take from it as you wish:

First you decide which general system layout you wish to follow: CHIFT-PIST or Chift2 - the great difference being, that in C-P things happen (mostly) in a serial fashion and in Chift2 you have a sump that supplies the FT and the GBs independently but with the same water(quality). MY CHOICE - CHIFT-PIST!

Then you need to decide to some extend what you want to do for growbeds - media filled, DWC or tubes (I don't call it NFT, because when used in AP I mostly do NOT see a Nutrient FILM, but a "river in a tube", kind of a fast flowing semi-DWC...

[In my case, I will try all of them, but the main idea is, to use the media-beds as filters for the DWC and tubes]

Now - what is the most SENSITIVE item in your system? To me it is FISH. So I want to make sure that I cannot hurt the fish by mistake - so, FOR ME - NO PUMP in the FT!
[I have no idea how long yabbies can take it without water - so I would place the pump about 1 to 1.5 feet above the bottom of your sump - yabbies will thank you, ....eventually!]

...so, pump needs to be in the sump. FOR ME - the pump will pump straight to the FT: With what I worked out so far, I can have a fairly low power pump arrangement and still get it air the FT just fine (venturies)....from the FT things will overflow to the veggie parts and eventually end up in the sump again. I will have enough spacing to put some kind of filter (or even a series) in-between all the major components, so I can test water qualities and adjust accordingly - RRF, MT, etc....

AT THE END - you can put the sump anywhere in the system, as long as you keep the rest of the components in a logical sequence so the water always can gravity feed into the next module before ending up in the sump. FOR MYSELF I will try to be able to pump from the sump to the FT, because this also implies that I have the cleanest water in the sump - least solids, least chance for pump damage/problems....

Obviously saving power implies that you do not have to pump to a high head, following, your overflows should not have to fall very much to reach the next module.
Here you will have to compromise somewhat if you use siphons, as they DO need some vertical space to work properly, but I did see some systems posts that can do with just a little more than the tube-size used!! (NO height below the siphon wasted...).
IF you need to change a lot of height from one module to the next (for whatever reason...), then lessen the negative impact and try to have the water saturate with oxygen - might as well use the fall height!!

I hope you can get SOMETHING out of this - don't hesitate to ask, if I didn't express myself clearly...

Cheers,

thjakits

Hi guys,

Yeah I think I might have my system all mucked up.

I'm now leaning towards having the tank with yabbies as a sump and the fish tank with an overflow (SLO) to the sump with yabbies.

Yes, I like the idea of having the pump in the sump up on a couple of bricks of something so there will always be a little water in there.

I can't gravity feed to my GB's so I was thinking of pumping up to GB's from sump (yabbies tank).

Would this work?
What would work best Bell Siphon (continual pump) or F&D?
Which would saturate FT with enough oxygen better?

Thanks all for those ideas and handy tips for my first system. Am still collecting parts to set up tank.

Regards

Ben

So I have tweaked my design a little.



After some sound advice.

Would this now work?

Extra water flow from Sump (yabbie Tank) back to FT to help with oxygenation.

Any other thoughts?

Would like to get all things down pat prior to starting the build.

Can't gravity feed from FT to GBs and pump from Sump to FT due to FT and sump being on same level and no way to change this. Also, GB's have to be placed above FT and sump. Just way the garden beds etc are where the set up will go.

Also, as I understand it the LSO needs to have an open end to the air to get the right suction?????????

Any idea how many fish I could run in the FT (Silver Perch) - Thinking about 20???

FWIW, given I'm a relative newcomer... It looks like it will work. Assuming your grow beds won't be too high to allow convenient access?

The open bit at the top of the SLO is to avoid your fish tank being syphoned empty. The suction effect on the bottom of the tank is due to the rate of outflow through the SLO... which is equal to the amount falling in to the FT from the GBs.

I don't think you'll need to have some of the water from the pump returning direct to FT... though it may be required if the pump is oversized. Better off having as much as possible go through grow beds - where it gets filtered and also where the plants get a good go at the nutrients. It will still help the oxygenation that way. If you get your water volume turned over every hour or so, you should have plenty of oxygen for the SP - they're far tougher than trout that way.

Following is based on my rough guess that you'll have 250 L or a bit less of wet media in each growbed (media to just below the surface of growbed and water level about 5 cm below). And, when full, each growbed will have about 125 L of water in it. (exact figures may vary between gravel and things like clay)

I've done my best to address the syphon vs flood and drain (and also constant flood) issue above. Both will work... but, the volumes in your grow beds look to me like your Yabby/sump tank only has about 200 L in it if your 4 grow beds are full at the same time - leaving little room for evaporation and transpiration to drop the level further... you might be constantly topping up. Constant flood will avoid this problem. Or you could have a mixture of constant flood and one of the two other grow bed drainage approaches... or have an even bigger sump tank.

1000 L of wet media - rule of thumb for fish is 20 - 30 L of wet media per fish planned to grow to plate size. So the good news is that you can have even more than 20 SP... in the end though, it depends on how much you feed them and a range of other unpredictable things... so better to start on the conservative side. I have a 1000 L FT (but not as much grow bed volume as in your better proportioned system) and about 40 SP fingerlings looked miniscule at the start but I'm starting to think that my remaining 20 or so are a bit cramped now they're getting to plate sized.

With a bit of luck, this post will bump your thread to the top long enough for one of the wise heads on here to weigh in.

Dave,

Thanks so much for the advice.

I didn't think about the water level of Sump after grow beds filled. Maybe I'll try 2 GB's with Flood and Drain and 2 with continual flood. Something like that. I'll think about it a bit more whilst getting all materials.

Thanks for the advice though.

Cheers

It's a pleasure Bunja. Will follow progress with interest.



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IF your growbeds are ABOVE the FT (and sump) you can pump into the growbeds - siphon from there into the FT and overflow into the sump!! IF you have too much flow from the pump, get yourself a RFF and have than one run back to the FT.....

thjakits

Yes... plenty of things that can be done with excess water from pump. Such as:

pumping to towers above your growbeds (heaps of threads on here about that) - works for me.

diverting some water to one of the myriad forms of external filters - including the very popular RFF type.

and even throttling the pump (though there seems to be some argument about whether this saves power and/or damages the pump)

Probably others I've never even imagined!

But I think that Bunja has posted about being a fan of the KISS principle and I reckon the most recently proposed setup will work very well without any extra filtration. As long as some of the beds are without bell syphons, there should be no problem getting all of the water from a sensibly sized pump through the biological and mechanical filtration provided by the growbeds.

I like this set up better for what you are planning to do. As already mentioned make sure you account for the water level in the sump needs to be able to drain all of the water out of whatever GB's you plan to flood/drain and don't want it to get too low when it floods the GB's, there are some pumps out there that have low water level protection to keep from burning up the pump. I'm using a jebao DC9000 which is rated at 2377 gph (9000 L/hr) max... I have been running it non stop for a little over a year in my saltwater aquarium and still very happy with it, being DC it has different speeds built in to the controller so you don't have to use valves to slow the flow. I am breaking down my saltwater tank so I am planning to use this pump to control the flow in my AP system so it should have plenty of power/head and can set the flow at whatever I need to get the turnover I want.

As for evaporation and keeping the pump from running dry, I will have an ATO on my system. This can be as simple as buying one of these float valves and putting a 5 gallon bucket of water with a hose run down to the float valve so it never runs dry due to evaporation (as long as you keep the 5 gallon bucket full of water). http://www.amazon.com/TOOGOO-Aquarium-C ... loat+valve

Hi Rininger85,

Nice idea with the float valve.

Will see how I go with my latest design first I think and then adjust as needs be.

Should be able to get a descent level in the sump so the yabbies are happy.

Will keep everyone updated.

Ben

I might go as far as to add rain gutters on my greenhouse and plumb it to rain barrels which then plumb to the float valve in my system that way the water level never runs low (as long as my rain barrel which would probably be 55 gallons doesn't run dry).