Recirculating slabs: Can you have too much runoff?

[blackone]

I was wondering how important it is only to have 10% runoff if you're doing recirculating slabs with drippers? If there is any runoff it already means that the coco is soaked and more runoff shouldn't matter much? I'm asking this because I'm considering coco but don't know for sure if I want to get myself a digital timer or settle for a cheap timer with 15 minutes intervals.

Obviously with drain to waste you don't want any more runoff than needed to flush old salts.

 

[rooted]

it won't matter as long as everything drains quickly back to the res. (don't want to flood anything over)

the additional recirculation will further oxygenate the nutes in the res.

the water will evaporate a little more but i doubt it's noticable

 

[blackone]

Ok thanks, wtf is that avatar of yours?

 

[rooted]

it's a mutant penis from some cheezy 80s movie

 

[aeric]

Splurge on the digi. If your pump is near big enough to do the job,(not some tiny decorative 30 gph pump) and u want less than 100% runoff (of course you do....)you're looking at just a few minutes drip time max. What's ten bucks when saving all those nutes, water etc....

 

[rooted]

he's recirculating, excess runoff isn't an issue when it goes right back in the res.

 

[aeric]

it still is....maybe 200% runoff max would be acceptable, probably a 5 minute drip in 2gallons or so. Mechanical timers aren't dependable anyways, no real accuracy, i stopped using it for my lights a long time ago when everything started re-vegging 4 weeks into flo....cuz of a lame ass mechanical timer Digis have battery backups in case of power failures, need i go on? 10 more bucks pfffff.

 

[V'd-Up]

ok i just bought a recirculating coco system for a cab and it came with a 15 min timer. what if that isnt short enough time? i have read where you need to feed coco 15 mins per hour for maximum growth, is that wrong are you supposed to go by runoff?

 

[NPK]

V, you can get a digital timer for $20 or less at Home Depot or Wal-Mart. They're cheap!

 

[rooted]

ya go for the digital timer....my point was that a few extra minutes isn't going to hurt anything in a recirculating system.

 

[raygun]

Get the digi timer. When running recirc you want to run multiple short times 3-4 times per day. Basically i have found you want enough run off to flush out the old and in with the new, and still allow the coco to dry/drain enough. If you put it on 15 min intervals you are going to have to work around the possiblity of too wet, or to dry between watering. I know coco you really can not over water but you can, just not to the point of instant death like with soil. It is more like "less than optimal conditions".

I run my timer 3 times a day once a few hours after lights on for 5-6 min then in the middle of flower for 3-5 min and then a few hours before lights out for 2-3min. I use 2GPH drippers and 1-3+ drippers per plant, depending on the water usage per plant as i currently am running multiple strains on a perpetual harvest in a cab. I have 3.4 lt. pots and run 6-8 plants at a time. I adjust the time frame for each water, or # of drippers, depending on what i see happening with the plants and coco.

This allows me the ability to run multiple stains of different moisture needs. At the begining of flower only one dripper as they get bigger i can add more without having to increase water times to all plants. If one becomes to wet i can remove a driper as well. If they all seem to need more or less water i can adjust the intervals for watering. It really is a great system now that i typed it out and think about it.

Hope this helps
~raygun~

 

[aeric]

yeah ray that is a good system, i like the manifolds with the +/- dials to adjust for different pressures, for the same reason.

 

[Harry Gypsna]

if you can afford one, get a decent digital timer or even a cycle timer.... ive found cheap diditals to be somewhat unreliable... over the past 3 years ive had 3 totally different ones all be suddenly resetting thmselves when runnng a feed- Its always worked out the same works fne for a while the one day u notice something screwy so you check...every time for me its been that theyve turned the feed pump on, but then when turning off, rest itslf back to blank, as in no time set either. Not really a good thing.
If you dont want a cycle timer then get the most expensive digi you can afford, you should be able to get one that has 10 on and off a day.....

 

[aeric]

Yep HG. Year after year i notice the same quality item gets more and more expensive, while the same price gets more crappy, case in point: digi timers. Go to any major hardware store and laugh at that crap.

 

[raygun]

Hey HG i am running a "cheep" $20 digi. i believe its a Intermatic and has been working ok so far for the last 6 months. How long did it take for your digi timer to crap out?
The one i got has 8 on off settings and is rated for up to 500 watts i believe.

In fact this is the model:
Intermatic 7-Day Digital Heavy-Duty Plug-In Programmable Lamp and Appliance Timer #DT27C

I am just worried that i might have the same issue as you down the road and don't want to.

Aeric - I have thougth about simplifying to the manifolds as i use to use those in previous grows and they worked out ok. They would always clog up on me however and that is why i stopped using them. But i also did not have an inline filter.

peace ~raygun~

 

[aeric]

I just filter the return. The manifolds have an internal filter though. I see crap floating in the res all the time from both Carboload and LK, attribute my clog free luck to a powerful pump...i think lol.