New Ebb and flow, Help dial it in!

Hi!

I am going to start with the specs of the grow -
4'x4'x6.5' = 104cf growlab tent
3x3 white ebb and flow table
40gal res w/ lid
400w hortilux HPS bulb
Yieldmaster 2 hood
standard sunsystems switchable 400w ballast
Ecoplus 4" 170cfm fan
tri-meter 204 ph/ec/temp
5" net cups with hydroton
cloned in rockwool
5gal jugs of drinking water ec=.05
30gal res heater @70F

Thus far I only have 5 plants on the table as i am waiting for more clones to root. The girls on the table were showing signs of heat stress about 4 days in but this wasn't really a surprise when i had a look at the temp in the cab, so i picked up the inline fan. since then the temp has not raised above 75F with lights and 69F at night. Leftover from the past couple grows i have the 3 part foxfarm ferts and thought well hell why not use them? Currently i am early in week 2 that the system has been running and res has not been changed.

Ferts & Water-
About 3 days after i mixed the ferts in the res i noticed brown solids remaining in the tray and at the bottom of the res. This could very well be the hydroton dust as well foxfarm food grade ferts. I already purchased advanced nutrients 3 part formula that will be here in a few days. When i change my res I will clean the tray and res before using new ferts. As for the ph/ec in the beginning it was going well but the PH and EC has been climbing slowly every day, this would make sense to me if the plants were much larger and res lid were off were evaporation and water consumption was actually taking place. These girls are showing signs of healthy rooting in the net pots but only 1 plant has a root that has actually reached the tray so they cant be consuming that much water yet. within a 24hr period the ph rises .2 so when it hits 6.0 i drop it back to 5.8 resulting in an EC increase of .1
Today i pulled 5gal out of the res and replaced it with 5gal of .050 EC drinking water and dropped the ph of 6.2 *after addition* to 5.8

Air -
I am not running an osculating fan on the foliage due to the size of the fan which i am using for exhaust. The inline fan is rated 170cfm and the tent is 104cf so that tells me if i am running the fan at max capacity there is 66cf of fresh air entering the tent every minute. Now i know its not running at its max capacity due to the duct work having a 180deg bend but nevertheless with the bottom intake vents being open, the walls of the tent are bowed in from the suction pressure of the fan.
Is this too much air? should i get a smaller exhaust fan and an osculating fan for the foliage?

Lighting -
As mentioned i am running sunsystems 400w ballast which is placed outside the tent on the floor, and the hood is tied at the top of the tent giving me 3' max from the top of the net pots to the glass of the hood. The idea is for SOG but if i need another 6" i will cut the legs down on the table, any more than that and changing/adding water in the res will be impossible. I havent calculated lumes yet but i dont think i need to, its close enough and after the first harvest i will know whether or not to bump to a 600w.

Please let me know what you think, what should be changed and how. I will post a few pics shortly, all i have is an iphone around the house so unfortunately the quality wont be great. Thanks for reading!

that isn't necessarily heat stress. As you see they are the lower leaves that are showing signs of stress. Not the highest top leaves. What percentage are you using the nutrients at? They are still young, and you never really want to use over 50% nutrient strength even that is sometimes too strong. In fact, just looking at your ppm that is PRETTy high for plants that are as young as those. Tune down your nutrient strength and the leaves should start to perk up again. For plants in Veg state at 100% nutrient level is around 1100 ppm, but i personally cut that in half, if not more.

As for the brown residue.. Did you rinse the hydroton before you used it? If not that is more than likely what it is. Rub a little bit of it, and if it feels chalky and doesn't really smear the changes are that it is not mold.

I really don't think it is heat burn, tune down your nutes, you can simply dilute the solution adding more water (doubling the amount of water to take it down to 50%). Also do you have an air pump moving the water in your rez? I found that that definitely helps.

And when you say drinking water? What is that, tap water? (Baddd idea) Also, the hydtron is what could b e throwing your PH off.

Give me more info and i could probably narrow it down!

Hope the info helps, more info and i will help again

Thanks for the reply BrannonC,

I started @ .6 EC and it has been climbing every time I drop the PH. It went from .6 to 1.0 EC in 3 days and has drastically slowed its increase but still climbing non the less. Rightnow since i have taken that picture the ph has gone up to 6.1 with EC remaining at 1.45. The water that im using is bottled 5gal jugs Polar purified drinking water from bj's since i dont have a RO as well the water here is not very good. I was hoping to harvest once using this method so it would pay for a filter. I did not wash the hydroton, i dont think its mold but the clones i just stuck in today i washed before doing so.

dude your nute meter read 1450 if that is correct then that is your problem... you need to flush you system with plain good quality h2o

also with a 400w you can be as close as 6-12inches from the top of canopy

You guys are right, it does need to be dropped. Im gunna have to wait til tomorrow after work but they will just be be in plain water for a few days until the advanced nutes come in.

Any thought on the exhaust fan with the suction pressure its building up?

honestly. The PH problem more than likely isn't actually a "problem". Since you didn't pre-wash the hydroton it could be a main cause of your PH fluctuation... Also, depending on whethere or not you pre-soaked the rockwool, that will deff make your PH rise as well. Adjusting it on a daily basis may not be required if the rockwool and hydroton are the main cause it is simply those factors making the PH rise, so adjusting it constantly is pointless because as soon as it hits the rockwool/hydroton it will make hte PH rise again. (That's your call, I personally adjust it every two days, but your call, it works well for me thus far)
You said that you have an exhaust fan, but do you have any fan bringing air in? The reason the walls are bowing is because you don't have enough air to replace the air that you are pulling out. You want to replace the air in your room as much as possible, as the plants always like fresh air. If you don't have a fan bringing air in, which it seems like you don't that is something that will definitely stunt the growth of your plants and drastically reduce your final yield. You said that you don't have an RO system, but you don't have a water store near you? They are usually everywhere and those stores usually have RO water, at about 30 cents a gallon. I think buying an RO system is a little over-kill considering you're really not growing on a large enough scale to make it worthwhile. Purified water really isn't good for the plants, almost as bad as distilled. You really don't want to use it, but if it is the best you can get your hands on, make it work i suppose.

And when you get the nutrients, use them at 25% strength don't just bomb it with 100% nute strength, start low, and let it rise. They have already been shocked and too much shock will turn the plants into hermes which you obviously don't want

Happy growing.

on another note. Put the rockwool below the surface of the hydroton. You don't want the light to directly hit the rockwool, as it destroys the rockwool and mold/algae are able to grow on the top of the rockwool which from the first picture actually appears to already be occurring.

pot actually thrives more with negative preasure and also help with humidity and pests!!!

BrannonC said:

on another note. Put the rockwool below the surface of the hydroton. You don't want the light to directly hit the rockwool, as it destroys the rockwool and mold/algae are able to grow on the top of the rockwool which from the first picture actually appears to already be occurring.

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for sure that algae could get prety nasty.. it doesnt hurt the plant much tho, but you should still cover it...

Thanks for your responses,
I have cleaned both the res and tray and filled the res back up. The water was not treated with ferts as i dont have any until tomorrow just super thrive so PH was not adjusted and has rose to 6.1 in 23hrs. Also res and tray seem to be staying clear of hydroton dust. We do not have a water store near by as i live smack dab in the middle of nowhere which is what drives wanting a RO, that and $6 per 5gal jug gets a bit obscene when you are getting 5/6 every 2 weeks during the winter and more during the summer.

I was always under the impression that rockwool even on a flood table should not be submerged as they hold a lot more water, if i were to bury the rockwool that would put it completely below the water level when flooding. This is ok? What you are saying about algae is true and all of the rockwool plugs have it, when i did ebb and flow the first time, after the plants were well rooted i tore the rockwool out as best i could without damaging any roots and left the rest below the hydroton. This is not the goal for the future, I already have a DIY 10gal 40 site cloner running.

As for air, negative pressure translates to bringing more air in than you are removing correct? I am unsure how this fan would perform if used as an intake but never the less that leaves no fan for exhaust on the hood. Do you think if i reverse the fan and suck outside cool air through the hood and into the tent that it would keep the room at a similar temp?

reggaerican said:

dude your nute meter read 1450 if that is correct then that is your problem... you need to flush you system with plain good quality h2o

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I've seen some people on here run 1400ppm from start to finish and they seem to do fine, but im with reggae on this one. I like to start new clones at around 500 and and come up 1-200 ppm each week after. i dont veg, but i also never really get my ppm's above 1250. I think you got nute burn since its starting in the tips. Also why the heater in the res. Colder water holds more oxygen and inhibits pathogens.

Well the plants are really loving the plain water, its already starting to bring the color back to the leafs. Advanced Nutrients came in, i have no clue why i bought 4 liters of each... maybe it was another stoned evening... anyhow i added 40ml of each in order and mixed in between each addition, this made the EC .48 and i will go up from here. I dropped the PH from 6.2 back to 5.6, this is starting become an annoyance since my buddy a few hours away is using his tap water and doesnt need to adjust his PH for an entire 2week cycle...

baggednismo said:

Well the plants are really loving the plain water, its already starting to bring the color back to the leafs. Advanced Nutrients came in, i have no clue why i bought 4 liters of each... maybe it was another stoned evening... anyhow i added 40ml of each in order and mixed in between each addition, this made the EC .48 and i will go up from here. I dropped the PH from 6.2 back to 5.6, this is starting become an annoyance since my buddy a few hours away is using his tap water and doesnt need to adjust his PH for an entire 2week cycle...

Click to expand...

when your ph drifted up, did the ppm/ec go up aswell? thats normal when theres too much ferts..

Is your buddy's set up the exact same as yours? Also, i would have flushed for another few days or so, until your plants come back to life, full of the green healthy color you are used to seeing. And dam dude, that really sucks that you are in the middle of no where. I get RO water for 30 cents/gallon which isn't bad. But over a dollar a gallon is ridiculous. What you can do to not submerge the rockwool is just put hydrton on top of it. You don't necessarily bury it just make it so it isnt exposed to the light. the algae on top of the rockwool may also be effecting the PH if it is deep enough into the rockwool. What you can do is simply take a spoon to the top of it and take off what you can.

happy growing,

yeah, it does kinda suck... when i lived in port st lousy there were about 5 water stores and they had water dispensers outside distilled or RO @ 25c per gallon 24/7
I will give the spoon trick a try here in a bit, it sounds plausible. Yeah my PH and EC were rising together, this setup is almost identical to my buddies except he has a smaller exhaust fan and runs his rooted clones to harvest @500ppm max as well never flushes in the final week.

I cover my entire tray with a sheet of panda film to eliminate algae problems. Cut x's in the film, put plants in place, tape up x's around the stem. keeps roots a little cooler. Noy washing your hydroton can cause ph bummer nightmares. I FINALLY got mine sorted out. Carefull about how much stock you put into everyone's PPM suggestions. I was following somebody's planting schedule something like 200 ppms first week, 300 the next and my plants were fucking starving for nutes. Popped it up to 900 and they absolutely took off. Yes 1400 is way to high, but don't under do it either.

whats the PPM of your tap water? Anyway you can give the readings in PPM instead of EC? That way I don't have to multiply

Is that panda film white? I noticed this on a few other peoples grow logs, it sounds like a great idea when i lay a whole tray out from the beginning. Right now im only adding 6-10 at a time as they root but shortly i will be able to supply a full tray of rooted clones each round so setup should be universal with the film each time. I guess the way i should get used to writing EC should be in formula, I do the math quickly in my head for EC to PPM but i depends on your conversion scale. I havent tested the EC of my water as my last ebb and flow didnt go well PH was all over the place until i got decent water so i wrote off my well water from that day forward. I will give it a check but i dont think its gunna be good... The water that i buy has PH-6.0 PPM-35@700/1

On that topic, I didnt catch it when it was mentioned the first time around but my meter reads in EC so 1450 that your reading is not PPM. It reads EC-1.450 or PPM-1015@700/1 or 725@500/1

Here are some pictures of the panda film. White on one side, black on the other..hence the panda part LOL, My table is wood so I just stapled it about an inch or two above the table using some scrap lumber. I'm sure you could rig up something. no reason you can't just add it now and then cut and patch as needed. I use foil tape cause its uber sticky. Start over if you mess up..its like $2.00 worth of film. You really need to keep the lights off your substrate for a number of reasons.

While your at it, make sure you have some panda film or mylar that hangs down next to your table if one side is not next to the wall (like mine is). The difference in light intensity with and without the reflective material was around 8k lumens. So nothing to cough at...

I don't have it hanging in this picture but its simply a 4 foot tall piece of mylar taped on the top and bottom to a length of 1/2 pvc I had laying around. I hung it from the ceiling and make some loops from bailing wire. When I want to mess with the plants I jsut fold it up and place the bottom pipe in the loops. If you don't know what the hell I'm talking about AND your actually interested I'll post pictures.

Cheers,
BB

BTW, doesn't everyone in north america use the 500 conversion?

Plants look fantastic today, root growth is great on all the plants. PH 6.1 PPM 245@500/1 res 65F room 74f humidity 42%
I have it this low because there are fresh rooted clones just added to the tray and i dont want to hurt them with nutes. they are rooting well so mid next week i will up their dose.

Im ordering some panda film tonight
I am growing inside of a tent it has mylar like walls, I went this route because with my first cab mylar was a pain in the ass. If you foliar feed the mylar ends up with crap all over it that just never comes off even if its scrubbed. the tent however has a mylar like reflective material thats easy to clean and doesnt wrinkle when its moved. I would like to take some pics of the whole setup but all i got right now is an iphone and the lens/light correction cant handle the lumens. the reflective material is doing a great job! the image ends up with lines through it and you cant see anything.

Your set up looks pretty good, thought through well. yeah, most north americans go by the 500/1 conversion because most PPM meters read in this conversion but if your using fox farm or advanced nutrients hydro schedule its listed at a 700/1 conversion. There not bad references to have on hand and it can keep you in check, as long as you follow the weeks as they go by. I really dont do a PPM conversion because my meter reads in EC and the schedules read in EC, since thats the most accurate number *calibrated correctly* its what i follow for a base. Understandably they may be saying to go up too high but i adjust accordingly, im shooting for 1/2 recommended schedule and will go up from there if the plants look to be starving.