Aquaponics build

[crsublette]

The water acts as the dielectric in between the plates of the capacitor. Changing the level of the dialectric medium (the water) changes the capacitance value. The higher or lower the water level is, the different value the capacitor has and the electronic circuitry reacts according to the changing capacitance value.

Catfishnut

Interesting.

I am familiar with conductivity gauge, but a capacitance gauge sounds really neat since it avoids all the problems with a conductivity gauge. But I wonder though... Wouldn't the plastic wall thickness act as a dampener interfering with the capacitance gauge? If so, I wonder what thickness and plastic composition they are working with.

Howard, do you know of anyone using a working model of this ??

 

[Catfishnut]

Charles,

The wall(s) of the tank become figured in when you calibrate the sensor. When the tank is empty of water it detects a specific capacitance value and when it is full it detects a different value.
Some sensors, though, have to be inserted through the wall of the tank so that the only medium in front of the sensor face is the water (or the air). At my work, we have sensors which sense through a plastic cylinder wall to detect plastic inside the cylinder. We're detecting the level of plastic resin beads for an injection molding machine. So, you see that the wall of the tank is not a factor as the sensor is calibrated to omit or ignore it and just sense the changes within the tank.

It works on the principles of a tuned oscillator circuit. When properly tuned with a specific capacitance value, the oscillator produces an output voltage. If you change that capacitance value even an extremely small amount, the oscillator quits and the output voltage drops or goes away entirely. It's really slick what you can do!

Catfishnut

 

[crsublette]

My concern is that a particular plastic composition or thickness would dampen the signal so weak that it would not be detectable, but it sounds like there is always some level of signal that can be read by the sensor. Very kool.

Lately, I've been playing around with one particular conductivity switch, outdoor hi-lo conductivity switch. I put mine inside a sight gauge, to reduce turbulence causing the switch to cycle on/off, but mineralization can cause problems so this switch has to be cleaned on occasion.

I wouldn't mind playing with this capacitance sensor switch. I'm not good at jimmy rigg'n to create a tool unless very good directions are provided. Know of a retailer for a capacitance sensor switch kit ??

 

[MitchM]

That sounds like a pretty sensitive sensor system.

I got most of the plumbing done this morning. I thought I had 5 1" valves here, but I don't,so I'll have to pick those up next time I'm in town, in the next few days.
I'm using a 24V/25W DC pump rated for 790GPH. Here's a picture of it with my smart phone for size comparison.
The media bed and aquarium volume should apparently be turned over once per hour, so this pump is a bit oversized. The volume between the media beds (once they are filled with growing media) and the aquarium is about 280G.
The pump is a soft start, which is nice, has 6 speeds plus a feeding mode. I will be using the feeding mode because being a reef tank, any floating food would be otherwise washed over the overflows.




The pump is in the 1st sump, and I've joined it with a union and teed off a garden spigot to facilitate water changes. We will just take water from the system weekly and water our dirt planted house plants.



The aquarium is plumbed to drain into the first sump.



I am going to be doing fishless cycling, so I have hooked up a canister filter to collect construction debris and help get the cycle going.
I am adding 50 ml of 5% ammonia and will try to keep the ammonia between 2 and 4 PPM until the bacteria population is established.

 

[HTH]

Last time I got technical somebody asked me if I was joking. Glad you guys understand this. If it can be made to work it would be a great solution. No I don't know of anybody who is using it. It just caught my eye in a app note and it has been on my mind since then.

http://ww1.microchip.com/downloads/en/AppNotes/CTMU 01375a.pdf

If sensing the tank does not work one could attach a pipe of some sort to it and sense the water level in the pipe which would be the same as the tank. Way to early to say we are out of options or it will not work.

Overview of the CTMU

 

[HTH]

Mitch the beauty of it is that there are no moving parts.

 

[MitchM]

I know! Plus only a 25W pump!
So far my water temperature is fluctuating between 18C/22C daily. (64F/72F) with no control in place.

 

[crsublette]

Very nice Howard. Thanks for the info. It is very interesting.

Mitch the beauty of it is that there are no moving parts.

Yeah, that's why I don't like float switches since too much can go wrong.

With that conductivity sensor I reffered to, all ya have to worry about is mineral buildup on the sensor, but, if you have a water pH below around 8, then there is not this concern about mineral buildup.

I put mine into a structure, somewhat like how Catfish decribed, and works quite well. Also, I like how it can handle up to an electric demand of 1680 watts, which is far above any aquarium controller I could find.

 

[MitchM]

Which controllers have you looked at? I use a Profilux and you can control 64 sockets over 12 powerbars that can handle about 1500W each.
Besides, I'm trying to go for less electricity, not more.

Are you building something Charles? Any pics?

 

[Waterbug]

I'd be more conservative on the ammonia level. I can't remember the exact level but these creatures can't survive or do well if ammonia is too high. If I remember right the nitrite converters are more sensitive and they're the harder ones to grow so to be keeping parameters optimal for them is the fastest cycle. Like I said, I can't remember the exact levels, but I'd stay under 1ppm. A little more work, but if you're after a fast cycle.

And I assume you already know this but I didn't see it mentioned...keep up the KH. These creatures consume something like 7 ppm KH for every 1 ppm.

 

[crsublette]

Yeah, I would definitely do a fishless cycle to jumpstart the bio-filter. The best instructions that I have found and that I use to very good success comes from a Dr. Conrad article from the 2009 spring/summer microbe-lift magazine; [sharedmedia=core:attachments:53349]. To help speed up the cycle, also make sure the magnesium, calcium, and bicarbonate levels are quite high and dose the water with some calcium bentonite clay (also called koi clay). If ya can, increase water pH to around 8~8.4 (primarily from the use of a bicarbonate product) and water temperature to around 72~77*F. Also, significantly increase aeration. The fastest I have seen a complete cycle is 3 days of a very high ammonia fishless cycle, but a shower tower was used with 72*F and 8.2 pH. I wouldn't use a shower tower since these filters have a higher tendency to oxidize the nitrogen (or lower nitrates) one way or another. There is talk of a heavily colonized "24 hour" cycle, but this talk seems to come from folk wanting to sell you a gimmicky specialized product. If you want to try a bacteria to jumpstart it, then check out Keeton Industries KI-Nitrifier Gel.

I have also read of liquid seaweed or liquid kelp will help decrease the cycling for this type of system.

Personally, I would not increase the pH above 8 to decrease the cycling due to plants simply just do better in lower pHs.

Since this is going to be an aquaponic (gardening) system, then I would not use sodium bicarbonate, that is baking soda, since the sodium component does absolutely nothing, moreso negative than positive, for the plants. Look into obtaining using a potassium bicarbonate powder. The potassium will become immensely beneficial to your plants, but do not add the calcium chloride and potassium bicarbonate product at the same time so space them apart by at least a day. If the potassium powder is a bit expensive, then you can mix a bit of sodium bicarbonate and potassium bicarbonate. The chloride component from the calcium chloride will help increase the plants tolerance to sodium, but I would not push the limits on this too much since too much chloride presence can create phytotoxicity concerns in plants. If you are concerned of dosing too much calcium chloride, then you can use calcium hydroxide (also caled hydrated lime), but the exta hydroxide component will consume some of your bicarbonate.

If you have or DIY'd a carbon dioxide reactor, then put in some dolomite. Dolomite is calcium magnesium carbonate, but this is tough to dissolve in water thus the carbonic acid created by the carbon dioxide reactor. The sulfate component of magnesium sulfate is quite beneficial to plants, but using dolomite might allow ya to use less calcium chloride or calcium hydroxide. Also, the carbonate (CO32-) portion of dolomite will increase your bicarbonate level whenever free hydrogen cations become available, which the nitrification process provides plenty of hydrogen cations.


I got a bit technical, but hopefuly it might give ya some ideas.

Which controllers have you looked at? I use a Profilux and you can control 64 sockets over 12 powerbars that can handle about 1500W each.
Besides, I'm trying to go for less electricity, not more.

Are you building something Charles? Any pics?

I have looked at quite a few aquarium autotop off systems. Quite a few of them involved much more computerization than I needed and would only handle pumps up to 1200 watts.

I'm using the, one I linked in post#48 for outdoor use, to switch off my 1500 watt pond heater in case the pond water levels gets too low in case of something happens, whatever that something would be causing the heater to operate while dry.

 

[MitchM]

Thanks.
I'm using this online calculator to tell me how much ammonia to add in order to reach a certain level of ammonia. http://www.fishforums.net/aquarium-calculator.htm

I'm going to be using Hydorcorn for the media, and I'm not sure whether it's going to affect the PH when I add it. I should have that added by next weekend.
Right now I only have the aquarium cycling, so if I have too much ammonia in there, it will be diluted when the sumps are tied in, hopefully in the next few days.

I'm not a big fan of adding specific chemicals trying to chase numbers, I'll have to dig up my water well report to see what, if anything, the water could be missing.
I'm mainly in leak test mode for now.

 

[callingcolleen1]

Ha ha ha ha, just had a good laugh... Saw your big beautiful tank in the greenhouse.... What are you going to put in there?? A BIG Algae Eater! He he he, just kidding
I had one too in my greenhouse, but all I grew really well was algae, could not grow even hornwort good, but I think it is because I had plastic on my greenhouse (glass much better), so not enough of the right sun to make my hornwort grow better than the algae. The water was also very cold as my tank sat on the cold floor. I can grow hornwort really well inside all the fish tanks in the house, but my greenhouse 30 gallon glass tank failed to produce lots of hornwort, maybe if I had a glass greenhouse the hornwort would do really well.....

 

[HTH]

This time I am taking a different approach to cycling with the 1500+ system of containers. I started doing a fishless cycle and the water went green.

So I encouraged the green water which the fancy goldfish people use to raise fish outdoors without filtration. Green water will handle the ammonia load and give the biofilter time to work,. The hope is that it will let me add a full fish load and cycle without ammonia problems.

When the water first turned green it was too green to see the bottom of the 2 foot deep containers. It then cleared to where I could see 2 feet but not quite 4. I think this is about the desired level of suspended algae. I added about a dozen fish from the pond and they are OK.

This is new for me so I will be testing the water but do not expect problems.

Colleen we have had shade cloth on our greenhouse for over a month. Venting it most days now.

 

[MitchM]

... What are you going to put in there?? A BIG Algae Eater! He he he, just kidding
...

Actually, I might. I've always had a soft spot for plecostomus. It depends on what the water temp does without too much intervention from me.