Hello!
I want to know about the use of the pumping system intermittently, thinking about not forcing the water pump and saving energy. Has anyone implemented it? Any information that can be passed to me?
Thank you!!
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Intermittent pumping is generally discouraged with the exception of small aquarium systems or seedling nursery systems which only need periodic watering. Turning pumps on and off can wear down the pump and shorten its working life span. Larger aquaponic systems for residential and commercial applications commonly use continuous duty pumps. The fish system in particular needs to have continuous water flow and a general rule of thumb is to exchange the full volume of fish tank water at least once an hour. This assumes a relatively modest stocking density between .2 to .4 lbs of fish per gallon. Higher stocking densities and feed rates can require a higher exchange rate of water to maintain water quality standards and effectively remove solids.
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As JD mentions above, Turning pumps on/off tends to shorten their life AND you will need to pump more water in less time (basically requiring a bigger pump to move the water in a shorter time.) So the savings you see for not running the pump constantly may be a false economy, think carefully about it.
That said, for small systems with very minimal stocking and small pumps, the most common way to do intermittent pumping is the plug in the pump into a timer and use stand pipes in the beds with holes near the bottom so that the beds fill to the desired high water level while the pump is on and then they can drain out while the pump is off.
Very important to keeping fish alive, if you are not running the water pump constantly, I highly recommend having a separate air pump to provide aeration to the fish tank 24/7.
In my systems, (large and sort of complex since there are different parts/methods going on.) I usually have some pumps that run constantly to provide circulation for fish, filters, towers/vertical growing, and raft beds while other pumps that feed seedling tables and other flood/drain tables will be on a small pump on a timer or there will be a continuous pump with a series of automated or indexing valves to sequence the flow through many flood and drain beds. (Sequencing and automated valves are not the way to go unless you are talking about a large system since the flow rates and pressures involved won’t work with a small pump and the costs involved in automated valves are silly unless you really need to be moving alot of water.)
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I wish we had had this advice before! We were running pumps intermittantly for our flood and drain growbeds at my last project.
We didn’t have any pumps fail, but we only had the systems up for two years, so perhaps not long enough to notice the extra wear.
We had a pipe which diverted excess water past the growbed, so if we had known this we could have built things differently.
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Thank you! Your answer is very interesting and clear
If you use a siphon, the pump runs continuously. It fills the basin to the desired level at which the siphon is set to activate. The siphon flow exceeds the pump flow and drains the basin, whereupon it stops automatically. The system runs continuously in fill and rain in this manner.