Cycle timing

[Sylvia Bernstein]

If you are growing using Flood and Drain on a timer, how often to you cycle and for how long?  I think most of us use 15 minute interval timers, so I'm guessing that the duration of a cycle is typically 15 minutes - I know mine is.  I tend to go 30 minutes between cycles if everything is nicely balanced and only 15 minutes between if I'm overstocked with fish and need the oxygen more than the plants need the dry period - which is where I am in 2 out of 3 of my systems now.  The other data point I have is Joel at Backyard says he typically goes 15 on / 45 off with his systems. 

What do you do?  What have you found works best, and what just doesn't work?

[TCLynx]

Yep.  It usually happens when a site gets beyond the first several hundred members.  Approaching 1000 seems like it's time.

[Sahib Punjabi]

Well said :-)

Chris Smith said:

There seems to be so much confusion on terminology it might be best if we make an  "aquaponics definitions" page to go along with "what is aquaponics" and "rules of thumb" on the home page.

[Harold Sukhbir]

Yes, it's really a modified NFT, I like that term and yes good suggestion about the definitions list Chris, i see BYAP has an existing one.

[Sylvia Bernstein]

Love the idea of a definitions list.  Harold, would you start a new thread with what BYAP has come up with so we can talk about it?  If consensus is that we like it - and my guess is we will - then I'll add it to the info section on the home page.  Great idea Chris!

[TCLynx]

oops started thread already

AquaGlossary

[Sylvia Bernstein]

I think you and I were hitting the 'send' key at the same moment 

[TCLynx]

[Harold Sukhbir]

Please use the initiative TC.

TCLynx said:

oops started thread already

AquaGlossary

[Sylvia Bernstein]

gotta move fast with TC around 

[Avery Ellis]

I am under the impression that a dry period for the grow bed is a good thing. My hydroponics systems tend to flood about 6 times a day(every 4 hours) for heavy fruiting plants like tomatos. But, for my Aquaponics system I decided to flood every 3 hours for 15 minutes each (8 floods/day) since I have seedlings growing now. This is allowing the grow medium to dry out enough to encourage the growth of strong roots (which I also inoculated with Myccorhizae). The seedlings that I planted seem to be doing great in this system, but I would increase the floods to every hour if someone thinks it would be more beneficial for the plants and/or the fish......?

[Sylvia Bernstein]

HI Avery.  You should turn over your fish tank water every hour in an aquaponics system for filtration purposes.  Tough for folks from a hydro background to wrap their minds around, but trust me...your plants will be fine. That media bed is the filter for your fish tank. I just had this conversation a few months with Boulder Hydroponics who decided to dial back their new-ish display system to the schedule you proposed above because they thought it would make the plants healthier... and then wondered why the fish stopped eating.  We tested the water and they had a huge nitrite spike.  Their plants actually looked fine, and will look better as the system matures (they were just trying to goose them because it was a display).

[TCLynx]

No goosing in aquaponics.  Gotta let nature take it's course or you likely pay.  Now I suppose some one with supplemental filtration to support the fish might be able to change the cycles but then you loose the whole efficiency of the plant bed also being the filtration.

 

I'd say if some one thinks the plants are looking poorly and they think it's cause the plants are not getting enough dry time.  Add more aeration to the water and you may see the plants perk up without changing the cycles at all.  Heck, I've seen plants looking really good in constantly flooded beds provided there is enough flow and aeration.