Backyard Aquaponics
A place to discuss aquaponics

I tried to attach my document to hopefully explain my system.... Re. evaporation, yes, I have to add water periodically to the system, depending on the weather.

The probes on each serve as signal sources for the logic controls in the unit. I did not want to have any mechanical devices on the system, as it would require a lot of problems over time.
Simply detecting the ":Full" level of either tank, without the logic controls would not work, in my mind.

I couldn't see your document, but I'd imagine that the sensors work like this:

When ft is full, turn pump on

when growbed is full, turn pump off

Am I on the right track?

Try zipping up your document, then you should be able to attach it.

Yep....

I really would like to see a diagram of your system layout as well... to determine just what it is you're trying to acheive...

He's probably trying to run a timed system without having those really shitty timers break all the time.

Had that thought Yavimaya.... damn them $12 timers...

Mine cost a bit more than $12!

haha i know what you mean rupert, but if i ever went with a timed system, i would pay the extra to have something i would trust more, but also something that you can "work with", which you cant with those timers.... computer promgrammable all the way.

I do like the none mechanical ones though.

Zipped and attached for Jack.

So.. I'm assuming the flood & drain is setup ala a "timed" overflow standpipe.... with small drainage holes in the bottom of the standpipe....

Question relating to "Model B".... with muiltiple grow beds.... is the flood & drain triggered to all beds... based on the sensor readings for a (one) bed???

Given the normal requirement for a sump with multiple grow beds... or a (relatively) large fish tank.... to circumvent fish tank drawn down issues.... a much larger pump would no doubt be required....

Is there a maximum wattage limitation for the controller???

One of the sensor probes appears to be copper based... what is the other sensor made of??

And are you aware of issues regarding the leaching/accumulation of copper in recirculating systems??

Similarly... with copper being a "soft" metal.... what would you estimate the life span of the sensor to be... under the usual acidic conditions encountered in aquaponics??

How much are replacement probes???

Have you experienced any problems with bio-film fouling of the sensor probes... an often seen problem with probe sensors in an aquaponics system???

Have you correlated the sensor initiation flood & drain cycle... with tank turn over volumes???

Is there a 240v model... or adaptor available?

What is the price of the unit?

Just re-reading.... seems to infer that there is a difference between Model A & B....

In that Model A suggests that the unit can (somehow) fill multiple grow beds sequentially.... does this require multiple sensors... one in each bed??

Rupertp'foz...Will attempt to answer your questions as follows:
Grow bed drain pipe holes, determine cycle time - yes
Model B uses one sensor on final GB filled in sequential filling operation....
Max. pwr for a pump , presently is 1.5 HP 110vac...(open to change)
Probes are copper and stainless steel, not aware of any copper leakage problems to date
Have run copper for 3 months, no problems with corrosion etc., can be easily cleaned as maintenance.
No problems to date with bio-fillter fouling that I know of.....
No 240vac model presently, but open to modification
Price depends on Model and any custom modification required
Tank transfer volume, estimated at 50 gal/hour
Multiple GB's filled simultaneously requires a sensor on each GB. (presently maximum of 4 available)

OK.. got that.... so what does the sensor in the grow bed do... just determine that the grow bed is full... and shut the pump off... right...

The sensor in the fish tank... recognises the tank is full... and turns on the pump.. right....


Doesn't make sense... according to your document....



Assuming that ... "Model B uses one sensor on final GB filled in sequential filling operation...." ... actually refers to Model A...

How can it work with only one sensor in the end grow bed... unless by "sequential filling operation".... you mean... cascading the flow from one grow bed to fill the next....

Until the sensor in the last grow bed detects "full"... and shuts off the pump????


Model B.... with multiple grow beds...filled simultaneously... requires a sensor in each bed....

But if the beds are filling simultaneously..... and/or one bed senses "full"... surely it will shut off the pump...

Even if the other beds are not full.... they wont be filled... until the water drains back to the tank.. triggering the tank full sensor... to turn on the pump..... by which time the beds may already be empty again....

What prevents.. or perhaps to put it better... what balances the flow into each bed... when filling simultaneously... so that they're all full... and not subject to a single sensor "off"....

And if in fact that can be achieved... then what's the need for a sensor in each bed???

I'm sorry... but I still don't understand it...



What's your pH... and how many/what fish do you have in the system???

Copper is known to leach in acidic conditions... and known to be lethal to fish and crustaceans... over time...

Bio-film build up.. and fouling of the sensors... may be a matter of time based on number of fish/feed rates...



OK... lets be more specific.... without any "user" modification requirement... what is the price for a standard...

Model A - 1 bed?

Model B - 4 bed?



If your grow bed is 30 gallon... then allowing for your media displacement... the actual water volume is probably more like 20 gallon... two cycles per hour => 40 gall/hour....

But is this actually the limitation of the pump... as much as the sensor time period??

If we assume multiple beds.... (and a correspondingly larger tank)... then the pump sizing becomes critical to hourly water volume turnover...

As if it's not big enough... then the multiple beds.. regardless of being filled sequentially, or simultaneously... may result in a long fill period, long drain period... and perhaps only one cycle per hour...

The same would be the case with larger volume grow beds... singular... or multiple...


Another question arises... in a multiple bed/sensor configuration... what is the maximum sensor cable length?

Here we go again...Hope this helps you out somewhat:

Know of no limit on sensor cable length... have operated at 50 ft.

Transfer Volume....My existing pump runs on 12vdc at 500gph... the pump is not limited in anyway, as it is designed to only fill the GB's and aereate the water in the fish tank while loading the GB(s) The full sensor on the GB shuts off the pump.

Mutiple GB's....Yes, using them would increase the pump time, as it is controlled by the GB being sensed. More GB's means more water being transferred and the time increasing, as the pump has a fixed GPH limit.

The MOD B waits for signals from up to 4 GB's, before it shuts off pump. If only one of the 4 indicates it is full, it will not stop the pumping, until all 4 are sensing FULL.

Fish... I only have goldfish in tank presently....problems finding live fresh fish... Ph is 7.6.

Cascading of GB's...MOD A only looks for last GB to be filled in sequence before turning off the pump. Once all GB's drain back into the fish tank, the cycle begins again...assuming a 1/2 hr. drain time, it seems the system should operate as planned. (unable to test this out as do not have that large a system ooperating)

Cost... As I am doing this as my hobby, the sale of a unit is based on material cost + my labor. With this in mind, and considering all Models are open to customizing, I would ask $75 for MOD A and $100 for MOD B. plus shipping. If interested, please let me know of address, etc. and Iwill send invoice for same.

PS I just finished the MOD D design, which monitors the soil moisture content and controls a residential sprinkler controller at 24 vac...Have it operating presently in backyard......using solar cell + battery.