Backyard Aquaponics
A place to discuss aquaponics

I have spent many days reviewing various ideas on watering/draining system for grow bed. But still not fully able to make up my mind on which system to adopt. While clay balls and gravels are being washed, I am still thinking about this when I have to do other things.

I plan two kinds of grow bed: large one is 150 x 75 x 30 (D) cm and another type is a smaller and shallow one 60 x 40 x 17 (D) cm, which may be called grow tray.

1] For the small and shallow, grow tray:

I liked the stand pipe system suggested by Food & Fish.
- Uses the standard 20mm PVC plumbing parts only, and
- the drain hole is not at the bottom of container but on side wall.
- There will be a minimum water height of about 2-3 cm defined a hole at lower part of standpipe,
- the upper height is set by the height of stand pipe,
- the stand pipe is to be covered by a 90mm down pipe with many holes at the lower 1/3 of height.

Reference: Alternative standpipe for timed flood & drain systems
viewtopic.php?p=86400

2] For larger grow bed:

After reading the result of the BYAP comparison test (cannot find the address at the moment), I felt that there was no special advantage of auto-siphone, and that a timer operated, flood and drain, stand pipe may be enough and of course far more simple.

If so, it appears that I could use the same system, discussed above, to be used the grow tray on the larger grow bed. The only difference would be height: longer maximum height (25cm) for stand pipe, and some what higher for minimum height (4cm) also.

Is my thinking reasonable?

Sejin

About 30 in number. Length 10-15 cm. One fat one is of a different kind.
Pond depth: 45cm underground, 47cm above ground, 5m long 80cm wide.
Gold fishes come to surface and I can touch them with hand immersed in water.
They are not alarmed and do not run away when touched.
On the other hand, 30 silver perch fingerings never come up to surface, and are quick to run away even under water.
I wonder whether they will become different as they grow and recognise their feeder.

This is not aquaponics. But an aspect of the Healing Garden.

Got ten bags of 50L hydrotron with intention of having the lower 1/4-1/3 layer with pebbles and the upper layer with clay balls.

Washing clay balls was relatively easy compared to washing of pebbles.
I put 3 bags in a 200L container and filled with water to top.
Because clay balls were floating, I stir them with hand.
Then, I used a meshed jug to fish them out to place in another container.
If needed, I can use the same method to give another wash.
Did not waste a single ball.

One could not do this with pebbles.
But there was another shower today to wash the pebbles in my driveway.

Sejin

The only thing I can think of that might be an issue is that you need to pump a lot of water. If you want to turn over all 5000L of your FT every hour, you are going to have to run the pump for most of the time. This will mean you will really be running constant flood beds.

That's probably Ok, but it might be relevant.

Found this comment by useful.

Brian Fanner
 Post subject: Re: Multiple Growbed Draining Method ?Posted: Fri Nov 25, 2011
viewtopic.php?f=1&t=11059

Just finished setting up one of two main grow beds with drain system and grow media.

Chose flood and drain with timer method rather auto-siphon.
Stand pipe is 20cm tall and the hole at the lower part of stand pipe is 3cm high. I wonder whether this is too high.

A 350 L size grow bed, gravel for the lower one third , and hydrotron for the upper two third.
Placing gravel into grow bed was hard work because had to carry by bucket for a 20 metre distance from driveway to backyard through laundry room. This house has no entrance to backyard except through house.

I now have to chose timer. Wonder whther i need more than one timer.
Originally, 5000L was has been circulating constantly by 8500L per hour pump through filter.
I am now adding two 350L growbeds.
I have a choice of controlling the amount of water going to each three destinations, filter, and two grow beds. Eventually the numbe of destinations will increase by adding two more gow beds and multiple grow trays, and possibly a strawberry tower.

Before purchasing timer, at the moment, i have half of water going to filter and another half going to one grow bed.
The second grow bed is yet to be filled. A bit of heavy labour, so cannot do it in one shot.

By an initial trial run, i noticed that it takes about ten minutes for 350 L grow bec to fill when no water is going to filter. Then it will take 20 minutes for two grow beds.

It took about 10 minutes to drain.
I made an adjustable size drain hole the drain time above is for a maximum size hole.

At the moment, it looks as if I can have a cycle of 20 minuites on and 40 minutes off.
Pond water did not become dirty when water was reclycled through grow bed.

Will now review the forum to see which timer to buy.

Sejin

The only down side to using timers for system system is that you might want to run the strawberry towers always on.

Does anyone have any experience with strawberry towers that stop flowing for 40 minutes?

Also, you have a 5000L fish tank that you want to keep turning over. If you go 20 mins on 40 mins off, just make sure you keep an eye on your fish to make sure they are getting enough oxygen in the water. Even with your 8000LPH pump, if you are pumping water up to 1.3 m above water level, to your grow beds, a bit higher to your smaller grow beds, a lot higher to your duckweed tank, and even higher to your strawberry towers, your flow back to the fish tank is going to be nowhere near 8000LPH.

I cant imaging it will be an issue with the number of fish you have, but it might be down the track.

It's good to see you making good progress.

I've just started a system expansion as well.

Strawberries don't usually like being constantly watered.... hydro strawberry growing uses timed irrigation..

I wonder if that's why all mine are dead

Interestingly, since I put my last two surviving strawberry plants back into my grow bed, they have sent out a most amazing number of runners. The count is still increasing so I cant give a final number yet, but I think I'll make a decent dent in replacing all my dead plants.

What regimen do strawberries favour?

Generally... acidic conditions... and well oxygenated... like in a grow bed...

Or in aerated NFT...

A mistake. Unnecessary work created.
I knew that the fibre glass pond tub that I am using for grow bed was rather thin, but I did not know how soft it was untill it was filled with gravel and clay balls.
Snow T suggest me to to timber under my grow bed. I was a bit reluctant to raise the height of grow bed, but I put a 19mm pine board under one grow bed. But the board was a bit short and did not fully support all of the grow bed.
When filled with gravel and clay media, the part not supported by the pine board sunk quite a bit.

In order to change the position of the pine boards under one and put new ones under the second one, nearly half of gravel and clay balls had to be removed. This additional work on top of the previous shifting of gravel by hand made me so tired.
But the supporting pine board job was done.

Even after many hours of rest, my back continued hurting. The fact that I am writing this means I am better now.

Finished plumbing,
had water tested,
got a timer hooked up set at 15 min on and 45 min off after measuring the length of time to fill up and drain grow bed,
then spread one grow bed with seeds,
and planted another one with purchased seedlings, tall ones in south side and shorter ones on north.
Asian greens that I used were produced in Japan.

Two 350L grow beds.
One planted with seedlings and another with seeds.
I am glad it is finally finished when I am getting back to paid work.

Now, I will have to wait and see the result before I add additional systems.

So far, I have been experiementing with floating draft on fish pond and grow trays unconnected to circulating water but fed with fish pond water.
The plants grown this way were not growing well. I am sure their growth would have been better if they were planted on soil.

This is why I am especially anxious to see the result of hooking up plants to a circulating system.

Will it be better?
Unlike most members, I do not have any result to show yet.
I do not even know what the result will be!

Before moving into strawberry towner, I will wait until I see some good result from the first system that was just set up. But it is good to hear that strwberry tower is OK with timer. I hear that strawberry tower needs only little water. There is also a debate on the best size of pipe used. I will be researching for the requirements for my additional systems.

Planned systems:

1] two more grow beds on high shelves;
2] 4 strawberry towers
3] two two level shelves along my fence (12 m) - that is 24 m long. Have to decide whether I put many grow trays, or create 6 narrow channels (about 2.6 m long) where I can put many pots.
4] Nutient tray channels under poli roofed pergoila.

Have you put my air pump into the duckweed?

If so, has it improved?

Duckweed needs ammonia, not nitrartes, so really needs a constant trickle directly from the fish tank.