Backyard Aquaponics
A place to discuss aquaponics

I wonder how much difference slime on it would make. Anyone know the thermal conductivity of slime?

I like it. That's one of those things where I have no idea why I need it, but I'm sure I will.

Filed away for later use/abuse.

Thanks

I've noticed that air temp and water temp only cross twice a day as the water temp obviously changes much more slowly than air.
I think that's an acceptable risk, chances of the sensors going wrong in that half hour when the temps are the same are minimal, well about 1/24 lol.
But as I said before, I wouldn't want a critical decision made on 1 sensor alone, the temp would give a nice backup reading.

That would be 1/24 multiplied by the chances of each sensor failing ofc...

I like my float/LED/Photo sensitive thinggy for water depth. Cost = 12cents and a bit of PVC + a floaty thing. I can imagine a lightweight float switch getting stuck after spending 4 years at exactly the same position.

You could use a glass jar or something with a bit of weight in it as a float in a PVC tube. It would be less likely to stick me thinks, and a bit slower to overreact to turbulence.

But then I'm biased, have no idea what I'm talking about, and I've never made one

So an LED on a float moving up and down relative to a phototransistor, or similar?
Complex mechanics and inherent reliability issues, not to mention calibration.
Assuming I have imagined correctly what you say.

yeah, kind of. An led stuck in the wall of a PVC tube with a cap on it. A photo resistor on the other side, and a glass jar with some black paint on the inside.

I cant see a lot to go wrong.

But I often don't see stuff

The little float switches could get stuck with a bit of algae set hard for 4 years. I cant see a glass jar in a PVC pipe failing to fall if the water level dropped. And the electronics are pretty reliable stuff for a few cents.

But like I said. I often dont see stuff

obviously the LED and censor would be on the outside with a hole drilled in so the inside remains smooth

OK I misunderstood slightly.
I thought you had the LED on a float and were measuring the amount of light hitting the static phototransistor at the top of the tube to give an analog reading of level.
If a simple on/off level sensor is all that's required, 2 resistive probes would, imo, be the most reliable.
No moving parts almost certain reliability something close to the MTBF of the CPU, ie roughly never

U could go a bit more expensive (well a lot relatively I guess), but more reliable and less stuffing around than bullie's idea and point a sharp IR range finder directly down the tube at the float.

Or an ultrasonic ping sensor if you wanted to go down that road.

Finally I got one of the new GB's finished.
Not been too well lately so not done much physical stuff.
Even after 3 coats of sealer and some silicone the plumbing still leaks.
One thing's for sure, my soldering is a lot better than my plumbing !


Forgot to go to sleep the other night and caught the sunrise

I was having a bit of an issue with my tomatoes and melons.
They were growing really well, but weren't flowering and consequently not fruiting (I have some in the dirt planted at the same time that are nearly ready to pick)
In another thread Huge Melons
I was told it could be a lack of Potassium, so I stuck a load more banana peel directly in the GB's and this is the result





Thanks again to EB and others who replied to that thread.

I have a team of (hopefully) strong people coming to build my new concrete underground and above ground sumps tomorrow, which will free up the 800L plastic tank to add more fish.
Progress on the concrete GB's has been slow, but it's coming on.

I'm looking forward to seeing it all up and running

Don't hold your breath.
As the ex-pats say here TiT.
This is Thailand