Backyard Aquaponics
A place to discuss aquaponics

Had the pump on a timer 1 hour on half off during the day
Now run the pump all day after reading it is better 4 the pump 2 do
the fish is the only things growing and the leaves r falling off

go back to using ur timer mate. The water needs to drain from the root zone to pull the air down to oxygenate plant roots.
If ur clever, u can run ur pump continuous but still flood and drain! Basically ur pump runs fast enough to fill but when ur siphon kicks in, it drains quicker than the pump fills. You get a burp at the end of the siphon and growbed starts to fill again. If u have a return tap to ur fishtank inline, it gives u a bit more flexibility to modify flow rates to the grow beds to get ur ideal flow.

I only have experience with this using a loop siphon, others may explain other methods of operating a continuous pump but still getting flood and drain.

Flood and drain without a timer is finicky, timer FTW

Yes, you can over water if there is not enough air in the root zone. If you have an air stone under every plant then it would be ok to keep flooded, but I think the bacteria do better getting exposed to the air often.

thanks guys thought this was the case

will shift sail over plantes to try and stop the rain

new pic

a good tip for dealing with the rain is to install over flow pipes in your growbeds and tanks.
that way the rain is nothing more then a free water change.

I have a really big pump and turning it on and off would be rather in efficient. So I use continuous flow but flood and drain with auto siphons and a flout. I've tried several methods of doing this.

There are several things you can do to help combat the niggly nature of getting siphons to balance right.
1-a bypass with a valve off the output of the pump back into the fish tank
This will help in several ways. First, by getting you more aeration and flow into the fish tank. Second, by letting you balance the flows and reducing the amount of work your pump has to do against pressure.

2-each bed should have a valve so you can tweek the inflow rate so that the siphon will start and stop properly. It is also handy to have a shut off on the bed in case you need to fix anything or have a leak in the drain.

I've had better luck getting loop siphons to work reliably and they do seem easier to adjust the fill height. I have gotten bell siphons to work properly but they do tend to require more tweeking and help in my experience. They also require more tools and parts to build. The flexible hose loop siphon just needs to be checked to make sure the hose isn't collapsing (flattening out) over time.

It is usually better for the pump to run continuous but if you can't let the grow beds mostly drain on a regular basis, you probably won't have much luck with most types of plants and your biofilter capacity may be greatly decreased.

Do some tinkering with auto siphons if you can and you will either like them or hate them. In the mean time, the timer might be your best bet. Good luck.

Does anyone know how many minutes before the roots start dieing from sitting in water?

I would say it depends on the plant... Some plants like water more than others. Some herbs for example rosemary likes fairly dry conditions, where as say tomatoes and zucchinis don't really mind it, my have grown in water their whole lives... Some plants on the other hand need it...

Doubt that it's measured in "minutes" Hunter... maybe hours.... think major floods....

What's more important is not just how long the roots may be submerged (flooded), but how quickly they drain and how long a drain/drying time occurs in relation to the "flood"....

As TimC says.... some plants prefer drier conditions... long drain/dry periods between floods....

Just think of a natural soil system and the plants that grow where and how in relation to rain or watering.... there's your answer....

AP really is just mimicking a natural process... albeit we exaggerate the flood and drain periods.... more frequently, but also more intensely...

i.e we flood fast.... but we drain even faster..... all about oxygen to the roots IMHO .... if you can get the oxygen to the roots then I don't think it matters how often you flood in a sense...

That's the beauty of siphons... the alternative is constantly flooded with high flow and oxygenation... ala DWC.... aka UVI systems

In my glasshouse running Scoria 1bed Vemiculite 2 beds Hydrotron 1 bed now runs 15 min on 2 hrs off

An example of a plant that will survive flooded conditions as long as there is enough aeration of the water is lettuce. I have grown whole crops in a continually flooded container with an air bubbler running in it.

The rosemary cuttings we put in one of the outdoor AP grow beds that I had a bell siphon in, are not doing well (all but two already seem quite dead) cause the inflow to outflow were not balanced quite right and the bed was staying flooded almost all the time. Other plants that are in that bed but seem to be surviving include tomato seedlings, okra seedlings (though having an aphid infestation), and onions.

I would not count the length of time in minutes but if you want a number to start with. Perhaps have the bed flooded for a half hour and the drained for a half hour, hour, hour and a half or whatever depending on the local conditions and the plants.

thanks guys
playing god is not easy