Backyard Aquaponics
A place to discuss aquaponics

I might suggest you put some hay around the bath tub if you want to keep the temp fluctations down from day to night.

Good, chaep, easy suggestion...

Yes thanks for the advice.

The hay thing sounds good. I was thinking about lining the bath on the outside with something for aesthetics but form and function go hand in hand

I want the setup to fit snugly against the wall and trellis. I could move the beds to one side which will allow me to see 1/3 of the bath. Not to concerned about fish watching but yeah will be handy tp have easy access. I do have a cat and dog but and dont want to expose the tank too much...

Going looking for some pebbly stuff tomorrow and the parts for syphon.

I have small wooden stakes round the tank and put some mesh wire around it then stuffed it with the hay to keep it compact.

If you dont run a sump, the water line will be at low tide when the siphon triggers. This will give you a bit more room to play with, but 5cm should just be enough anyway.

By far the simplest way to get a siphon working is to put a tap so you can adjust the amount of water going to your grow bed.

The size of your siphon depends on your pump, or if you have more than one grow bed, the rate of flow to the particular grow bed.

Most people aim to turn over their fish tank water once every hour through the grow bed.

Do you already have a pump? if so what is the flow rate per hour? If you dont know, time how long it takes to fill a jug or bucket of known volume and work it out.

Make sure you check the flow at the height it will be flowing into your grow bed(s). Pumps lose flow the higher they have to pump.

If you dont have a pump yet, consider getting one way too big for the task, because you WILL be expanding your system/new obsession . It's easy to divert flow away from your grow beds, and back to the fish tank if there is too much with a 2$ tap. The fish will love the extra flow.

Cool thanks for the reply.

I have put my pump and solar setup in place. Its covered for now with a sheet of perspex to keep out the rain. Picked up some scoria and blue metal pebbly stuff for the main grow bed which is awesome. Found the scoria at a landscaping place for $9 a 20 litre bag. Gave them a good wash in my wheelbarrow and then a garden sieve.

Next problem...!

My pump doesnt want to work. last time was last summer/autumn and it was working fine. I suspect my battery (deep cycle, jetski type) maybe needs replaced.... not sure as my multi meter is broken. Will get a new one today i reckon.

Pump is 12.5 litres per min. When it was working it was real good

So i dumped the water out by hand. Then realised my siliconed plug actually pulls out. None of the stuff stuck to the plug but there is now a smaller rim of neat silicon. But also a very small leak. Should be easy enough to fix

Heres some more pics:

Good to see expensive electronics perched on the rim of a fish tank

I think that pump is using a stack more power than it needs to. I'm pretty sure that pressure listed is enough to pump out of a well, or up a three story building.

If you end up having to buy a new pump, look into this kind of thing instead. That way you might be able to get away with a smaller battery or a bigger system.

Cool you mean the 1350?

I have a smaller pump i was gifted a while back. But its AC.

That pump was running just fine off that setup last year for a few months. Well i got myself a new multimeter so i will go and test it out.

Well i finally got a multimeter that works! Dont buy the cheapo one

My battery is reading 1.3 volts. No good.

Time to buy a new one.

another option is an air lift. There is some interesting work being done with zero head systems, where the grow bed and fish tank sit side by side and the grow bed is kept constantly flooded.

Very experimental though.

I have seen an airlift thingo used to aerate a compost tea. Using an airpump.

Same thing ish?

Yeah, you can move a lot of water by pumping air into a tube that goes from the bottom of your tank, straight up.

Have a look here

Yeah sweet that looks good. Especially if it saves power for a solar setup. I was looking around for dc airpumps a while back but and couldnt find many.

Also i really want the beds on top of bathtub.

If i get the pump to work with a new battery how do i match up the size of pump vs size of bell syphon?

If you tell my your flow rate, I can take a stab at it, but as far as I know there's no formula.

The main this to do is make sure you have a tap on a T so you can divert some water back to the fish tank. This makes it really easy to adjust the flow and get it right so the siphon triggers, and stops.

in my blue barrel grow bed, I used a length of (I think) 12mm internal black pipe from the hardware store. I think they might be used for pop up sprinklers. They are threaded at both ends and the one I bought is around 20mm long.

With my old pump, there wasn't enough flow, but the good thing about those threaded pipes, is that a length of 12mm poly pipe fits inside it, so it was easy to scale down. I didnt worry too much about leaks as it all leaks back into the grow bed anyway, so I didn't even seal it.

So my advice would be to use a pipe that a smaller pipe fits inside so you can change it.

Put a tap just above the pump so you can waste a bit of water back to your fish tank. It all helps with areation, so it isn't really wasted, but it means you can tun it Up or DOWN.

Then adjust the tap so enough water flows to start the siphon.
Then if it wont stop at the end when the bed is empty, turn the tap down slightly until it does stop.

Adjust up and down a bit each time - it will probably take 5 floods and drains to get right.

There is a range of flows that will work for the triggering, and a range of flows where the thing will stop. The ideal is somewhere in the middle of each of those ranges so there is a little forgiveness in the set-up.

The other option is to start with a smaller hole and pipe, so you can drill it out larger if you need to, but I'm lazy so I went bigger with an inner sleeve as a backup plan.

And yes the 1350 pump should be enough for a 1000L system.

But if you plan on going bigger later, you can over size without drama by dumping more water back to your fish tank for the time being. You can always add a timer and tun the thing off for half the time or more.

Depends how big your plans are.