Backyard Aquaponics
A place to discuss aquaponics

Ahhh of course - For the constant flood beds I would need an additional pump to run them. D'OH! Forgot about that!

But then if I have to buy an additional pump I might just be better off splitting my beds in two and simply running two separate flood and drain systems instead.

Lots of permutations.

With respect to system volumes. My beds are 55 litre containers, so given that I would probably not fill them 100% with media and the water would sit 20mm below this level I could potentially see about 45 litres of water per container. So given that I have 12 beds that's a possible 540 litres if I were to use an auto syphon setup or flood and drain with a single pump.

My pool says it holds 1250 litres, but I'm not 100% sure how they arrive at that figure. At any rate I'm getting towards half of the water volume in grow bed size which I'm guessing is not too good as far as fluctuations in levels is concerned when running flood and drain.

I'm thinking I need to address the fluctuations as much as possible, especially given that its easier to do it at this stage than later down the line.

Nebbian, I've given a bit of thought to the 15/45 timing and as you point out the biggest limitation is the fact that there are only 60 minutes in an hour - this means that a 4 way valve is the largest that can possibly run on a 15/45 timing. (4 x 15 mins).

This in turn means that the best I can achieve is a 135 litre fluctuation if all 12 beds are run flood and drain but in banks of 3 using a 4 way valve. (540 litres divided by 4)

So 1250 litres (pool volume) less the fluctuation of 135 litres leaves me with 1115 litres in the pool at all times.

This seems to work quite well. Maybe this will do the job.

Is there a supplier of these valves in Australia?

Mick

Mick, I am the exclusive supplier of the aquaponics valve in Australia...

Although potentially with all your beds pumped full at any one time... the draw down on the tank is as you calculate....this is rarely the case even in siphoned systems... (although each/all beds must initially fill before the siphon is activated)...

In timed flood & drain... there are two 6mm holes drilled in the bottom of the standpipe (for the drain when the pump turns off)....

These holes begin draining as soon as the timer begins pumping to the beds... but can't drain faster than the pump fills the beds... hence the water level rises.. and overflow the standpipe...

But the point is... and remains through out the flood & drain cycle... that water is returning from the grow beds constantly... until they're actually completely drained...

Thus the water draw down is not the full nominal amount of the grow bed capacity...

I still think the valve is overkill for your situation... the size of the grow beds...

Anyway PM or email me if you want to discuss it further...

Note that 50 litres of growbed, filled with 50 litres of media, won't then hold 50 litres of water as well. Just something to consider

Just rechecked... and I posted an extra zero in my other post as well....

Although your containers are 55l... say 45l of actual usage.... the media (depends on type).... will displace 40-50% of the volume...

So your actual water fill... is more likely to be 20-30L per bed...

So your maximum draw down on the tank... will only be about 240-360L... which is just fine with a 1250L fish tank....

As above... I don't think you have a problem... and anything to gain from sequentially filling them with an aquaponics valve...

Unless you're thinking of adding more, and/or larger grow beds...

Edited : Ah Nebbian.... you're on to it as well...

As a comparison Vdubber.... your total grow bed volume is 55 x 12... 600L.... and a fish tank of 1250L...

The BYAP Entertainer system... has 2 x 500L grow beds... drawing on a 1000L tank... with timed flood & drain...

No problems...

Ha. I'd read this and would think that every 15 minutes the fish are without water.


Good advice guys.

(Of course the media displaces the water why didn't I think of that D'OH)

Given the advice, and the fact that other similar sized systems work with no issues, I recon I will set it up without the indexing valve. Saves a few dollars and makes the system simpler as well.

Unfortunately no more progress to report this weekend as I have been busy putting up a fence in the front garden, will hopefully get back to it next weekend. Might sketch out some details for the frame this week so that I can figure out how it all goes together.

I'm sure the will be some more questions along the way.

Thanks for the help.

Some things to think about or that might be useful;

1. With Constant Flood you can just fill everything at the maximum level you want and go with it. Adding beds just means you add a bit more water.

2. Running CF reduces the number of things that can go wrong since
a) there is no timer
b) the pump doesn't have to restart over and over.

3. You can use a smaller pump although it will always be running. May not save you money on electricity but the pump might last longer because you aren't always turning it on and off.

Design the piping and growbeds in CF to hold the water, if the pump stops the tank won't overflow.

It's pretty simple to switch back and forth - Drill a hole for timed flood and drain at one end of the standpipe and leave the other end without. Flipping the standpipe and changing the pump cycle is all it takes as long as your standpipes are the correct length. You'll probably want to add or remove some water depending on which way your going to run the system.

Hope this helps

[flash=][/flash]

This is a good point, the less there is to go wrong the more reliable it should be.

I think my initial impression when researching was that I could run syphons for the flood and drain and still have some beds constant flow with the pump running constantly but then realised that I might have a problem with FT level fluctuations if using auto syphon and not controlling how many beds were filled at the same time. But having now resolved that issue I guess I can consider using syphons again which means no timer.

Ideally I would like to run a mixture of CF and F&D beds due to the variety of veggies I would like to grow (some don't like to be permanently immersed), plus it helps reduce the variation in FT level.

I'm currently in the middle of creating a spreadsheet for the stuff I want to grow and figuring out what conditions they like and when the ideal time to plant is (based on the stuff I've read for dirt based gardens). This will likely drive how many beds I run CF / F&D. Being able to easily change between CF / F&D would be a great bonus as I can see that the planting arrangement will likely change seasonally.

One thing that I have read in relation to certain plants that cannot be planted together is that they should not be planted in the 'same system', however, I could not find a good definition of 'same system'. Does this mean same grow bed? within a certain distance? or literally in a system that shares the same fish water? Any help here would be greatly appreciated.

Mick.

Concepts of "companion planting"... are usually associated with a particular plant feeding heavily on a particular trace element.. depriving another plant of that element....

As we are supply nutrients to all the plants... all the time... in aquaponics... other than attraction of benficial insects... most of the rational for companion planting is negated... as are most of the soil based spacing suggestions...

Well I've been pretty busy since I posted last and my system is now almost up and running. All I am really waiting on is for my media to arrive.

The system has been cycling for a week now using the media from my old trickle filter from my old tropical aquarium (masses of plastic pot scourers - much cheaper than 'bio balls' ). I threw a couple of clams in the pond to kick start the process, it's also been getting the water changes from my sons goldfish.

I pick up fish tomorrow morning, 30 silver perch. I opted for these as they are evidently very hardy plus will not eat each other. Once things are up and running I will look at swapping some fish out and introducing some smaller / larger fish at a laster stage so that I have a variety of sizes in stock, but that is a dilemma for another day.

As pictures speak louder than words here's the progress so far...



Pond in place and erecting some posts to support the frame



Trial fitting the brow beds



My boy Locke making good use of the pool



Welding up the frame. I opted to use fence rails as I had some 'in stock', these are used on their end for strength



Frame in place - test fitting the GB's again.



Frame mounted on wooden supports and top rail in place. I used reclaimed oregon pine for this.



I clad the sides with some corro that I had spare and finished the corners with some flashing that I had laying about. I knew that one day my hoarding would come in handy



My take on the standpipe - I used these iron to plastic water pipe adaptors - 25mm Poly to 1 inch iron. They do both a male and female so work perfectly for use as a bulkhead fitting. It also gives a perfect 25mm fitting top and bottom



I used a 90mm waste cap for the bottom.



and added a 25mm poly irrigation fitting to the bottom - it presses in perfectly.



In the top I used 25mm poly irrigation pipe for the stand pipe and 40mm waste capped off for the bell syphon. I opted to leave out the additional small diameter hose that I see people adding for a syphon break as I couldn't see the point in it. The syphon will break when all of the water is gone.



My 5000 l/h pond pump



And here is everything all plumbed in and working. I opted to use poly irrigation pipe for all of my plumbing, it's cheap and worked on my tropical aquarium for years. My only issue was that I originally had a pickup pipe attached to the inlet so that it picked up from the centre of the pool (see previous photo), but I found that it very quickly became clogged with leaves (the AP setup is next to a deciduous tree). This is something that I will need to look into.



Here's the flow at the outlet nearest to the pump. The main water supply 'ring' is 25mm and each outlet is a 13mm tee.



Here's the outlet furthest from the pump. The flow is noticeably less, but not so bad that it is an issue.

Originally I was worried that I would have to regulate the flow so that each outlet was more balanced but the setup works really well.



Another shot of things in action.

Interesting to note is that quite often all beds are pretty much full at the same time, most of the time at least 6 out of the 12 beds are full with the rest filling. However, even with no media in the beds the impact on the pond level is minimal. I measured the pond and calculated that I probably have about 1300 litres in it and there is still room for more.

Tomorrows task are to pick up the fish and run permanent power out to the AP setup from the garage so that I can get rid of the extension lead that it is currently using. I will also look at getting some seedlings started. Fingers crossed my media will get here Monday or Tuesday.

it looks like you'll have a pretty intesting time come fish harvest!

looks great... but what about fish harvest?

It looks a lot worse than it is - it's pretty easy to access the whole pond with a net from outside.

And the last resort - it's easy enough to lift a GB out and climb in.

...Or drop a line in and wait

I figure it can't be any harder than trying to catch a fish in my marine tank - full of rock with plenty of places to hide

flick some lures... i would (and have )

Well the fish are now in. Picked them up this morning from 1Aquaponics in Two Wells here in SA. Andrew, the guy who runs it was very helpful, took the time to answer my questions and gave me some good advice.

I bought 30 Silver Perch, which have settled in nicely, although they look a bit lost in the seemingly massive pond.

Here's a shot of the little takkas before they went in