flood & drain setup

[duc750f1]

Can someone advise me on how long to water for a flood & drain setup,using 50litre pots with perlite. How much runoff should I see? Shop told me 1min feeds 3-5 times per day, with a few litres runoff.

[Guest Wilderbud]

Perlite breaks up very quickly into sludge [which blocks the pump and tray filter] in a flood and drain setup - Id go with straight expanded clay [itll move around a little until the roots have grown in but it doesnt break down as fast as perlite]. I havent tried vermiculture as it messes with PH but it might be more useful in a flood and drain setup.

 

Im pretty sure I had a water cycle set to 15 mins every 4 hours using perlite+expanded clay. I would try it every 3 hours if it was straight expanded clay although it all depends on the amount of medium and heat you have also.

 

PS. dont put rockwool or moss in your tray as they may stay moist and rot your stem.

[white_cluster]

perlite doesnt turn to sludge at all. its fine. a good mix for flood and drain is perlite/vermiculite 3/1.

vermiculite turns to sludge when used as a medium by itself, but that takes a while. Its inert, doesnt cause any pH problems at all.

all mediums require pre-rinsing before using, vermiculite and expanded clay both need alot compared with perlite.

1min is not long enough, usually you set the pump on a timer and they have 15min cycles. If your tray overflows with 15min cycles than your pump is way too powerful, must be huge, or your outlet hole in the tray too high or skinny.

Ive never tried expanded clay as a flood and drain medium, but I cant see how it can be good as it wicks no water at all. the only area roots will grow is the area that gets flooded and a few inches above.

 

If you use a perlite vermiculite mix, run the pump twice a day for 15 mins , then increase after 2 or 3 weeks to 3 times a day.

 

rockwool is a very good medium for flood and drain especially slabs, obviously needs less watering than a medium such as expanded clay. I hate rockwool myself because it rots and stenchs, and needs alot of flushing, but flood and drain is the way to go if you use it.

[WhiteSkunk]

hey all .

duc750f1,first up using 50lt pots aint flood and drain .....

its run to waste and if u run 4 15min well your throwing alot of money down the drain in a recurculating 50ltr pot perlite system u would run @15 per 3 hours..

but in a run to waste 50ltr pot perlite setup your feeding should b 5 min @4 feeds @18hrs..and 2 5min feeds@at 12/12....

and if you r useing horshoe feeder rins then drop it down to 2min feeds..

and as far as perlite turning to sludge well ive neva seen or had that happen in 17 years of useing it! cheers all

[duc750f1]

Hey all, sorry for misleading you with my question. White Skunk is right, its a run to waste system. Got my terminology wrong. I'm using a hose the size of an airline in a ring shape with 4 outlets around the plant to disperse the water. I'm feeding 5-6 times per day for 1min, and getting about 30-40litres runoff a day. Plants look Ok, but having previously used a recirc system, where I was feeding for 15mins every 2 hrs, I feel that I'm starving them of water.

[ScuzZ]

You're definately wasting too much fluid.

 

You should only have to waste approximately 10 Litres a week or fortnight depending on the dependancy of your plants.

 

Measuring your PH is the best way to indicate when to waste as well.

 

15 minutes for 2 hours is a bit lean, up it to 10 minutes per hour and you will maintain a healthy oxygenated solution. This will also reduce the chance of bacteria growing on your root system and rooting medium.

 

Choices of rooting medium are personal preference, as long as they're PH neutral they're all good.

[duc750f1]

Huh? 10 min feeds per hour would go through heaps of nutrient in a run to waste system, since a 1min feed dumps about 5 litres.

[Ozzy420]

I was was runing run to wast for my 2nd grow, i had my timer set to water for 15mins every 2 hours an a drip system from a 30lt res, i only had to refill the res every 4 days i was growing in strate perlite, i dont know if this was too much but to me it seemed rite and my babys had no probs from what i could see so i will be doing the same againe but instad of useing 100% perlite i will be putting in a 70/30 mix of perlite/vernic so it holdes a litle more water

 

p.s if any 1 thing of a way i can better this please let me know.

[Tom]

Check out the "my hydro set-up" link in my signature, its run to waste.

[Guest weekprik]

perlite doesnt turn to sludge at all. it

 

I used perlite in my flood and drain system and it DID turn to slush, it blocked my pump as well,

 

The only good stuff to use in a flood and drain system in my experiance is hydroton, yes it doesnt wick, yes its inert, which are both necessary in a flood and drain system,

a/ you dont need it to wick at all, thats the whole idea of the rocks in a flood and drain system, It doesnt need to look for food as its flooded with more than enough food to last till the next feed.

b/ Hydroton will not hold water, but that means the roots can recieve more oxygen than a water holding medium, the roots grow through it nicely, and always seem to about 1/2 fill my stacker boxes.

 

as far as the rocks moving, yes they do this if there is not enough stones or the water level is too high, but to avoid any problems you can use net pots without sox, well you can use sox as well but then theres a chance of becoming root bound as the sox stop the roots being able to leave the net pots.

 

sorry I know we worked out its a RTW but just wanted to set this right incase flood and drain ppl are reading this.

Edited October 2, 2003 by weekprik