help with flood n drain timing

[jumpincactus]

I am running a Flo n Gro 12 pot system. Media is Hydroton with mesh inserts. Just got her up and fully installed.

I am struggling with the timng of the flood and drain cycles. This is my first stab at hydro so I am very green (no pun intended)

Would some of you fellas using a flood and drain system help me out with figuring how often to flood and how long to keep flooded and just an all around idea of where to start with the cycles.

I appreciate any and all constructive input from those that have gone before me.

Peace

 

[mmjvet]

timer wise, what do u have in mind ?

 

[OG13]

We flood once after lights on, once middle of "day", once before lights off. Test run before plants are in to verify the level of flood and integrity of all connections. Make sure all buckets are filled during the allotted time. But Jakester is correct, watch the plants, the Flo n grow is capable of much bigger plants than Cap's system due to the larger buckets.

 

[HydroManster]

The growing medium and environment should determine how often and for how long you flood.

With rockwool for example you could get by with once a day or even less, with hydroton you would need to flood more often.

Using grow stones which is IMO the best medium to use for hydro, flooding takes place every 4 hours for 15 minutes.

Cheers!

 

[Twelve12]

It really depends on the plant maturity, light, temperature, humidity, grow media, and size of your hydroponic system. Need your setup info!

Plant maturity: All plants transpire (water evaporation through the leaves). The bigger the plant the more it transpire. That's how the plant feed itself by taking up nutrients from the roots through the body and out from the leaves. Young plants require less flooding.

Light: High wattage, duration and proximity is something to consider. These affects the transpiration rates. The closer they are the more transpiration it will occur. Same with lights of higher strength. If you're using 1000w consider flooding more per hour vs using a 250w and even less when using florescence (T5, T8, T12 HO) or compact florescence (CFL).

Temperature: This is a combination of room temperature and the heat produced from your light(s). The hotter it is the more transpiration the plant will give off. By keeping your temperature between 65-75F you don't have to worry about temperature effecting the transpiration rate. If your room is above 80F during the light(s) on then consider flooding more.

Humidity: Keep in mind that high humidity or RH (room humidity) for vegetative growth. Low RH for flowering. When the plants are in veg growth it does not need much flooding since the leaves can soak up the water like a sponge. When RH is low the environment is dry which will force the plant to transpire more. Great for flowering not so good for veg unless you increase the flood time to replace the water lost. Since flowering require low RH flooding more can only increase yield (with the right nutrient strength).

Grow media: Since you are using hydrotons require more flooding. The rocks does not retain water for long. So increase flood time is required. Other medium such as coco or rockwool can retain more water require less flooding.

Size of your hydroponic system: Having a large and deep hydro system require less flooding. Due to its size and depth the water can sit for awhile. If your system is shallow it will need frequent flooding when factoring the temperature, plant size, grow media and RH.

Take all these into consideration when adjusting your timer for flood frequency. Giving that the lights are on for 16 hours, for hydrotons flooding 4-8 times a day should do it. That's once every 2-4 hours. If your light is 600-1000w and the temperature is 80F-85F consider once or twice per hour during the lights on. No need to flood during lights off. The key is not to let the plants dry out during the lights on. Even when we think the medium is moist it does not mean the roots are drinking.

 

[OG13]

Study up on Pythium. What is the temp of your reservoir?

 

[OG13]

Are the roots to the bottom yet? If so, run the cycle 3 times during light on and see if it improves.