Backyard Aquaponics
A place to discuss aquaponics

I just finished putting together my small grow bed and the timer I have will only fill it once every other hour
that is if if I want it to fill and empty it 24 hours
basically my question is if this enough or would it be better if more fill and drain cycles happen during the day and I can just have one or two during the night?
or I could spend the next day or so tinkering with what I have around to make a float switch

How long does it take to fill your growbed? ... and how long to drain the growbed??

I'm wondering if filling the grow bed during the day at least once every hour is better or if filling it every other hour 24/7 is better

Don`t forget to take account of the fishtank volume too.
If the tank turnover rate is too low, ammonia build up in the tank could become an issue.

Generally people use a timer based cycle of 15 mins ON and 45 mins OFF... 24/7....

As Hex suggests... this may or may not be sufficient in relation to your tank volume...

More information please...

I'm using a 50 gallon aquarium with a under gravel filter to help break down waste and add oxygen to the water so ammonia buildup due to lack of o2 or lack of surface area hindering bacteria growth shouldn't be a problem unless I'm much more missinformed then I think.
The GB is 5 foot long 2 wide only 6 inches deep but I plan on growing things that will get used whole quite a bit and I will probably give worms in the bed a try in hopes of avoiding root problems.
only have 5 small fish right now but plan on adding some gold fish tomorrow.
I'm interested in how the fill drain cycle affects plants and how light affects how plants take up nutriance.
Ao basically if having more fill drain cycles during the day and maybe 2 or 3 at night would be better for plants or if spacing out the fill drains over the course of the whole day and night would be better?

Also would slowing down the how long it takes to drain be beneficial at all as currently it takes me 5 min to fill the bed and only 10 to drain and if I have an hour till it fills again then that is a while for it to just be sitting there.

before you can call it a grow bed


sorry, I had to finish the line

i dont think its going to matter too much.

i'd probably go with a "every other hour" but set the drain rate to take as much of that time as possible.

the answer seems to be blowing in the wind

If you have the oxygenation under control via other means, then the gaps between are drainings are less relevant. Therefore main considerations relate to 1. sufficiently exposing water to the bacteria to allow ammonia - nitrite - nitrate conversion process & 2. Providing plants with sufficient water.

With hourly pumping the second should not be an issue - except perhaps when plants are very small and if media used and the weather conditions lend themselves to rapid drying.

The first depends upon your nutrient load - ie number of fish. Obviously the longer it takes to drain - the more exposure in your case.

I'd personally be inclined to buy a timer with more on/off cycles. Here in Aus they are only about $10 for one that has 15 minute increments for the full 24 hour period.

so does the number of times the gb fills have less to do with plants and more to do with the fish being kept happy?

Yep, plants once established can go over 12 hours without water being pumped to them, but unless you have very few fish, they wil get sad as the ammonia increases.

I modify my pumping regime to suit the fish load in my system, bigger fish = more growbed flooding.

I have been pondering about very slow filling and very slow draining each spread over approx. six hours, synchronized with the movements of the moon so as to mimic the tides
wonder if that would please the plants?

frank