Cleaning New Gravel and Pipe Size

Cleaning Gravel:

Yesterday I cleaned about 5 cubic feet of new gravel.  In the past I have used progressive tubs and a bucket filled with holes.  I would start at one end and work my way down three or four barrels of progressively cleaner water.  This proved to be insufficient and the barrels became quite dirty very quickly which meant that I would constantly have to start over with more clean water.

But yesterday I used a small cement mixer.  Id put 10 shovel fulls of gravel in and filled it with water.  Then turn the mixer on for 15 seconds, and dump the water.  I did do this about 7 or 8 times until the water was running clear.

This next step may not be necessary, but then I did a final rinse in a white bucket.  I was able to easily see how clean the water was in the white bucket, and two quick rinses generally finished the job.

It took a few hours to perform this cleaning, but after several bad experiences with cloudy water, Im very happy with the results.  Today my water is perfectly clear.  

Pipe Size:

A couple months ago I added 10 feet of 1-1/4" pipe to the line from my fish tank to the grow bed.  It has worked well until recently when I noticed that the water in the fish tank was beginning to raise.  Closer inspection of the pipe revealed that gunk had built up on the surface and was slowing the water down.   I replaced the pipe with a clean 2" pipe.   Ill let you know in a few months how that worked out.   Im feeling confident that this is going to work out much better.    As a general rule Id say 2" or larger pipe should be used everywhere.

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Aquaponics Self cleaning swirl filter revisited

One of the many people named Anonymous took the time to comment on my self cleaning swirl filter, so I thought Id revisit the topic with some thoughts Ive been having.

For the last few weeks Ive been thinking of getting some more fish.

And Ive also been thinking about developing the self cleaning swirl filter a little more.

My original design was to tap off a small amount of clean water for NFT tubes employing the self cleaning filter to keep the roots from collecting solids and blocking the NFT tubes. In the end I got around that by just taking my water from the sump, where there were no solids, but that required a better pump to get water to the top of the tubes. .


If this were ever to be implemented as a system to remove solids from a system rather than returning them to the grow beds it would need some adjustment.

Its easy to set up a container so that it is right at the point of tripping a siphon, but will never actually get there unless someone suddenly dumps water into it. With this in mind, one option I thought of  when I was playing with this idea, was to use a deer scarer...

http://en.wikipedia.org/wiki/Shishi-odoshi

Set a dripping tap, so it slowly filled a deer scarer. The deer scarer should tip only once or twice a day, and should dump the same amount of water that the self cleaning swirl filter takes from the system each time its triggered.

Im going to build a deer scarer, and see how it works, then see if it really would take care of dosing the self cleaning filter with the correct amount of water to make it do its thing.

You can see my previous work on my self cleaning swirl filter here.

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Stirling engines Slow motion balloon power piston

I made a few adjustments to my little tin can Stirling engine. It now spins twice as fast, at a rate of around 210rpm. Not that that means much because the more flame you put under it the faster it goes. But its around twice as fast as it was originally. Quite a success as far as bettering a terribly inefficient Stirling engine goes.

If you ask me.

The main adjustment I made was to replace the two sections of shaft that make contact with the supports. The original shafts and bearing surfaces were made of galvanised fencing wire.

I replaced them with a thinner grade of stainless wire. Actually its welding wire, and is the same stuff I use whenever I mention stainless wire in the construction of my fishing lures or anything else on the blog.

Pictured here in this uncomfortably framed, but interestingly red image, is the new wire, the old wire, and a match.

The thin stainless wire makes a huge difference. It even runs without the 8g counter weight now.

The counter-weight is there to mirror the weight of the displacer, so without it, the power piston has to lift all that weight on its own.



With the counter-weight and a minimum sized flame, it can now tick along as slowly as only 32 rpm.

Stately.

To run as slowly as 32 rpm, I found it also needed a small drop of very light lubricant (fishing reel/sewing machine oil). But its important to note that the shaft for the displacer - the one that goes through the small hole in the can, should not be oiled. The oil burns, and leaves a sticky residue which will stop the engine.  As seen by the improvement by the slight reduction in friction, the smallest extra friction will kill these little engines. Use graphite, or just leave it with nothing.

If you did lubricate the displacer shaft, its also possible that oil or Vaseline could get into the displacer container, and being flammable, might eventually find its way to igniting if everything was just right.

Everything is very rarely just right, and a Stirling engine is a very safe thing to make and use because there are no pressurised containers. The making involves some sharp bits of tin can, and should probably not be built by kids, but as a finished item, its as safe as any small candle is, so probably qualifies as relatively child friendly.

Lets say... As child friendly as a birthday cake.

Anyway, it looks like this in slow motion (sorry for the poor picture quality)...

[edit from the future - Opps, for some reason the video wasnt dropped into place.] Here it is...




Even more stately.

Its currently clunking away on my desk, running at around 60rpm on these two little flames, and has been doing so for an hour. One flame is about the size a birthday candle, and the other is around half the size of a birthday candle.

My point is it isnt using much heat compared to the last version.





I find its sounds...

oddly soothing.



K-chunk K-chunk



120 Things in 20 years thinks that if ever I disappear, it might be because Im off on a Stirling engined bike trip around Australia... in slow motion.

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