Solar hot water - Aquaponics - NFT worm

[Edit from the future - there is some additional material on NFT ]

That previous post was meant to go out 2 days ago, but I saved it as a draft instead of publishing it.

That sums up my life at the moment.

I'm in draft mode. I found one of my fish dead, on the concrete yeaterday. I'll post about it when I know a bit more about it.

But I did take the time to check the water level in my NFT test, and discovered that not only was the water very hot, but there was a worm in it.

My worm looks like he's all broken and sore, but when I gently teased him out, it tuns out he was faking.

Perhaps he's in labour.

I've always thought that those large, white, thicker sections on a worm indicated the presence of an egg. (seen here on the left in pink)

One of the dangers in always thinking something, is that it might not be true. With anything you have known all your life, there is a fair chance your older brother was the source of the information at the worm wise age of five and a half.

I'll look into it, and if it turns out it's important, I'll let you know.

But the reason this post is in solar hot water, is than on a 17c day, I'm finding my water in the NFT tube, within the grow house, is 36c. I'm pretty sure worms don't like 36c so I moved him back into the main system. There is also the danger that something like a worm could block the plumbing and cause an overflow.

I'm guessing that's a little hot for strawberry plants as well, although they seem content enough.

That's not bad from a heat collecting position though, even if it isn't so good for a strawberry or worms position.

The strange thing is, I'm collecting all this heat from a white PVC tube, that I thought would be one of the cooler sections of my grow house. It's making me rethink the way I might go about collecting some heat to make a solar hot water heater.

The other strange thing is that the air temperature in the hothouse is 29c.

I think I might have a hot house within a hothouse situation going here.

If so it might be very easy to concentrate some pretty hight temperatures, making storage of the heat a lot more compact.

NFT test

[Edit from the future - there is some additional material on NFT ]

As usual, this is one of those things that I just made in the hope that research wasn't necessary until I had failed at least once. I really don't know things like how much nutrient rich water to flow through, exactly how deep the water should be, and, well, everything else. What I do know is that you cut some holes in PVC pipes, stick plants into the holes, and pump water through the pipes.

So I started with what I know.

I cut some holes in some pipe. This will be for seed raising so I'll cut the holes close together.

I'm hoping to be able to move plants around at will to maximise the growing space I have.

If I can move plants, I can grow them densely when they are little, move them to the medium density area when required, and then to the largest spaced holes for a while before harvest.

The plan is for small plastic pots to sit so that they touch the bottom.

And a trickle of nutrient rich water will pass through the base of each plastic pot.

Because I'm still using my sad old pump, I'm a bit limited as to how much flow I can offer the NFT pipe, so I'm stating with a only a broken stream from a 4mm (external) pipe. Basically at the rate of a dripping tap.

Next I added a 90 degree bend, and a short extension with an end cap. This should allow me to adjust the depth by slightly rolling the entire pipe and bend, so that the outlet pipe sets the desired water level.

I was going to make it so that the end cap could be rotated and thus the exit pipe's height adjusted, but it was a better option to seal everything properly (I used plumbing tape for this because I might want to pull it all apart if it doesn't work), and just rotate the entire unit to adjust water depth.


Here's a hot tip I discovered.

Its possible to make a really good seal with clear plastic hose, by drilling a hole that is a bit too small to pass the pipe through.

Cut a slice off an end to make it taper to a point.














Pass it through the hole.

Then grip it with pliers and pull like mad.

With a bit of effort (the more effort required, the better the seal) you can get a very good seal.

Simply pull it all the way through until there is the desired amount of tail on the end inside.

This will be the drain hole, and emergency overflow in case of blockage.




Having said that, clear plastic tube isn't very good for aquaponics, it gets a build up of algae on the inside, and will eventually block. This is just a test, so I want everything to be removable, and I also want to be able to see water draining, but in the final version, I will use black poly pipe.

So my final product looks like this.

Water enters through the 4mm pipe to the end on the left out of frame, and runs through until it drains back into the fish tank, through the elbow, and the clear plastic tubes.

If all goes well.

Now I can pull my new strawberry seedlings from the blue barrel, and add them to the NFT pipes without disturbing them.

This top down view shows the thin black pipe that delivers water just jammed into the hole on the side of the pot, but it will eventually have its own entry hole drilled right at the very end of the pipe.

The seedlings are already showing roots peaking through the bottom of the pots, so they should be just right for transplanting into the shallow water.


In the dirt world, you would have to transplant into ever bigger pots, but I'm hoping that in aquaponics, there will be no need, as the pot really just becomes a convenient handle to move the plants around with, and less to do with how much access to nutrient they have.

Who knows. I'll let you know more as I find it out.

[Edit from the future - there is some additional material on NFT ]

Aquaponics - Hot house

A few days ago, I bought a little hothouse.

It's actually surprisingly well made, as far as the frame goes.

I have no idea how long the cover is going to last, but I'm assured it's made of UV stabilised plastic.

If the plastic gives out on me I'll recover it with a thicker, more rigid poly carbonate sheeting.

It works. It's hot in there.

It's my new office.


The shelving will come in handy, as I'm planning to add some NFT channels or something similar, to expand my growing space.

NFT or nutrient film technique usually has 1 or 2 millimetres of nutrient rich water flowing through  pipes with a series of holes cut in the top. Small pots sit in the holes. If you've ever bought a lettuce from a supermarket with roots still on, there is a fair chance it was grown hydroponically, in NFT channels.

I think I might go a little deeper, and have a little more flow to keep everything cool.




I also just discovered these tie down things in my shed that I didn't know I had. They work like luggage tags or those single use handcuffs, and I cant help thinking the way they ratchet will be extremely useful for something down the track.

They're also very useful as tie downs.

[Edit from the future - there is some additional material on NFT ]

Aquaponics - Fat Film Technique

I bought some of these in the hope that they would fit into my thin film technique tubes.

It's actually a seed raising tray, but the pots all come out of the tray so I thought I'd be able to use them.

It would of course involve throwing away the tray, the plastic wrapping, the cardboard advertising on the front and back, and the reciept, but that shouldn't pose a problem for me as I'm a white middle class man from a developed nation, so waste is in my genes.

But it gets worse.

They don't fit.

The pot should be sitting on the bottom of the tube, or really close to it.

I should have measured* twice, bought once.

But like I said I'm from a middle class background, not a ruling* class one.





I'll take them back and try something else.


*Bada-bing!

Aquaponics - Nutrient Film Technique or NFT

One of the best things about setting up an NFT or Nutrient Film Technique aquaponics system, is that I get to use PVC yet again. I dont know why, but I love the stuff.

As far as I can tell, Nutrient Film Technique, involves planting plants into little pots that sit in a channel with a thin layer of nutrient rich water flowing at their roots. The water is only one or two millimetres deep, so most of the roots have plenty of access to the air they also need.

I'm guessing the water migrates at least part way up the roots in that way that water does, but who knows.

Oval cross section NFT PVC tubes

Some time ago I got hold of these two PVC, oval cross section pipes.

They are currently sitting in the rafters of my shed, but I think its time to pull them down and incorporate them into my life in a more meaningful way. Not that I have anything against sitting in rafters if that's what you're into. But for me and my PVC, its all about getting down and being attached to a fence or something.

I have no idea where to get the cups from so I'm not sure If I'll have to make them or if they are an off the shelf kind of prospect.

Either way I'm going to have a go at this NFT caper, and see If it might be a way to get some additional real estate for my strawberries.

The plan, at this stage at least, is to attach them to the fence behind my little aquaponics system.

With a little slope built in it should be possible to pump water up from the fish tank (hose drawn in orangy-brown*), have it flow through the top tube, and empty from the left into the bottom tube(sloping slightly to the right), where it would then flow to the right and empty back into the grow bed or directly back into the fish tank.

Those green things are my stunning illustrations of strawberry plants.

See how they thrive?

Thrive plants thrive.

Plans have a habit of changing around here, but it should work. If it does work, I should be able to move the strawberries around, so that when they put out runners (strawberry plants put out runners (runners are little baby strawberry plants sent out on a stem to set up home next door to the original plant (generally speaking a very sensible way to reproduce compared to all the carrying on everything else does))) I can set up a situation where there are vacant spots on either side to accommodate the runners.

[Edit from the future - there is some additional material on NFT ]


* Yeah! That's a colour!