need some advice about watering rockwool

[420blunts]

wuts up IC'erz . wus wonderin if anyone can give this noob any pointers about watering rockwool and what to look out for when using rw as a growing medium. got 12 purple kush babies in 6" rw blocks. i've been watering them everyday now since transplanting dem into the 24hr pre-soak 6" blocks. so far this is my watering schedule

Day - 18/6 veg - ph @ 5.8 - tap mix w/ ro water ppm @ 150 - hand water 1 gallon for every 3 rw blocks
1 - 350 ppm
2 - 350 ppm
3 - 150 ppm water only
4 - 400 ppm
5 - 4000 ppm
6 - 150 ppm water only
7 - 450 ppm
8 - tomorrow

nutrients i've been using
advanced nutrient
micro-grow-bloom
fulvic acid
b-52
voodoo juice
jumpstart

i have tarantula & piranha but was scared to use it cuz it didn't dissolve when i add it to the mix the first time. will it be ok to use them both with rw even though it doesn't dissolve ???

my g-room temp right now is 74F lights on & 70F lights off. humidity stays between 48% - 60%

questions i can think of right now

Do i really need to water rockwool everyday ??? (especially right now since they are still small)

I have my 1k mh light about 4ft above my girls, is that high enough ??? (did the hand under the light test and felt no discomfort wut so ever.

The ph on the run off is always at 6.2 or 6.3, is that normal or something i am doing wrong is causing that ???

Any pointers will be greatly appreciated ! Thank You !

 

[koidr]

Frist off could use more info and some pic's to much water once you soke the 6" you should not water for 2 days only water when the blocks are light.Sorry only saw the frist part of your Q.4 foot is fine temp is fine iam gussing day five is 400ppm not 4000 it would be nice to see pic's you are def. over watering. Hope this helps

 

[420blunts]

thanks koidr for spotting that typo. day 5 was 400 ppm, my mistake. today i won't give them anything, but i will check on them every 4 hours just to make sure they can make it thru the day without it. if i only need to feed them every 2 days that would be GREAT. sorry about not having pics. i wanted to add the pics i took but my usb port ain't responding to anything i plug into it. got an ancient desktop in front of me. wut other info should i add to get more help.

 

[RockyMountainHi]

ok now I just started growing in rockwool , here's mine about june 6th and yesterday

June 6



and today





Out of 38 starts - I still got 38 and of those, 3 are not running well; the rest all look very good or beter.

I've been told water daily, after 2 days the drop in water tends to make the chemical swings worse. And the manifacturer web site agrees. Some growers water twice daily. Part of the advantage is drainage leaves 15% oxagen or summtin like that so even when wet, the roots can get air. Now we know soil plants like to dry a little - so they get air, but rockwool is more like coco-coir. now for the finnaky 3 - two of the three look overwatered! but when 90% of the garden is rockin - phhhhTTTTTTTT!


They also say don't flood and drain with rockwool, but that is the system I'm using.

 

[420blunts]

thanks for your input rocky. yours girls are nice and perky. i was told by the hydro store guy that the top of the rw blocks should be covered to block light from damaging roots. don't know how true that is but i have 6" coco-caps covering mines since they didn't cost much. good luck on your grow. decided not to give my girls anything today. will feed tomorrow and check the ph run-off and see if it jumps from the regular 6.2-6.3 .

 

[ourcee]

They also say don't flood and drain with rockwool,

lol?

rockwool is PERFECT for ebb flow (flood/drain). if you are using 6" blocks you cant really flood as effectively as a drip system would water, anything smaller than 6" is bitchen for ebb/flow however.


no real need for 6" unless you're going to veg them for quite a lil while. (or use them for mothering?). me personally I like 4"x4"x4"s with the hole, (i use rapid rooters to root cuttings). they are the perfect size for a sog or medium size bush. any bigger and I'd rather put a 4x4 on a rockwool slab than have a big ole 6x6 though (personal preference)

when you soak them, you need to soak them in ph'd water... i'm guessing you might not have? (hence the runoff being higher)

and if these are small baby clones then yes you will only need to water every other day at most at the get go. however as the plant increases it can/will want water more often. up to multiple times per day (if needed/plant size depending)

your temps are perfect, however I'd move the light closer, right now I have a 1000w MH conversion over a 3x3 table and its only ~2 feet above the plants (roughly 8 inches or so tall rooted clones)

 

[420blunts]

hey ourcee, the rockwool blocks were pre-soaked in ph 5.5 water for 24hrs. i knew i should of let them dry out and pre-soak them again for another day with 5.5 ph adjusted water. my girls are still small so every other day will probably be better for now. my 1k light isn't air-cooled so thats why it i have them that high. just to be safe.

 

[ourcee]

hey ourcee, the rockwool blocks were pre-soaked in ph 5.5 water for 24hrs. i knew i should of let them dry out and pre-soak them again for another day with 5.5 ph adjusted water. my girls are still small so every other day will probably be better for now. my 1k light isn't air-cooled so thats why it i have them that high. just to be safe.

I soak mine in (very) light nute solution, ph'd to 5.5 5.8ish for about 30 minutes, then pop in the clone/plug and water again when its obviously drying. (usually a day apart or so at first) what I do is just pull back the cap and feel the top of the block with my fingertips, if its on the wetter side of barely moist, it doesnt need water. the tops will dry out faster then the bottoms obviously but just throwin that out there. so I water when the top is starting to feel actually dryish.

and yes you should definitely cover the tops of your blocks, you can get by without, however will probably build up massive amounts of algae which wont really do you any good soooo good call on capping them. I only use the lil plastic squares with a slit/hole cut in them, haven't used the coco caps, only difference I could think of is that they would help with water retention near the top, just fyi.

and the plants can handle the heat radiating from a bulb, it will be a couple of degrees hotter closer to the bulb then far away, however if your ambient room temp is 70-74 and youre circulating the air around with a fan of some sorts, i.e. the whole room is that temp. then you could move your light to 2 feet or so above them and increase the lumens at the canopy as well as all of that fun photosynthesis stuff that plants like to do, all while minimizing stretch. The plants can handle 75 degrees all day long in rockwool.

 

[lysol]

My package said soak in 5.8ph water, no need to soak for any extended period of time. ( grodan mini blocks ). I soaked them and even poured a few ml of nutes into the tray and covered. They get fairly dry after like 16hrs even if theyre completely soaked. At first my seedling started to bend over but i picked it up and ( leightly ) squeezed out the excess. going good now. no extended soaks, no extended dry periods or anything. The package says to mist the block with nutes as it is needed so that is what I'm doing. I read somewhere some growers even just weigh the blocks and try to maintain a steady weight.

 

[ourcee]

I've found that when people are new to hydro and using some sort of water retention media, i.e. rockwool. Most people will tend to over water rather than under water. Over watering will make them root slower/less effectively and slow the growth down due to the roots not needing/wanting to 'expand' to 'find' water. They tend to look slightly droopy when over or under watered, I look for nice perky flat and horizontal leaves 'reachin for the sun' as my perfect balance. Not saying you are overwatering, just sayin that the "perfect balance" in watering takes a minute to find and get a feel for.

clones/seedlings need hardly any nutrients added to the water really, however a very low PPM is better than zero. (make sure its pH'd)

 

[Wait...What?]

why do people do this

if these are cuttings and not seedlings,
FULL STRENGTH NUTES

and even with seedlings, aside from the first couple of weeks, there's no reason NOT to run FULL STRENGHT NUTRIENTS unless you are just trying to stress the plant, or you don't have enough light to properly grow indoors.

not enough light to grow is the ONLY reason not to use FULL STRENGTH nutrients.

and you didnt buy enough stuff. thats only like 8 components to your nutrient mix. you need more stuff that conflicts with the other stuff and gets the ratios out of balance. ITS ABOUT BALANCE. [now repeat that out loud to yourself three times.]

 

[ourcee]

why do people do this

if these are cuttings and not seedlings,
FULL STRENGTH NUTES

and even with seedlings, aside from the first couple of weeks, there's no reason NOT to run FULL STRENGHT NUTRIENTS unless you are just trying to stress the plant, or you don't have enough light to properly grow indoors.

yeah fuck the nute burn he'll just flush it all away right? I've had shitty over fertilized weed and you CAN tell the difference between an over fert'd plant vs one that was never over fed. Dont tell me that a small clone can handle 1500 ppm without getting nute burn.

not enough light to grow is the ONLY reason not to use FULL STRENGTH nutrients.

or it could be that the plant has no need for 1500 ppm while it has a mere 4 fan leaves worth of vegetation, that it will probably need an absolutely minimum amount of water over the course of several days as the plant is consuming such minimal amounts of both water and nutrients. The plant cannot and will not take in more nutrients if its already consuming them as fast as it can. Excess of that amount (easily found with a simple ppm pen) is just wasted nutrients and stress for the plant, all while building up those tasty chemicals you just love to smoke later on down the line.

and you didnt buy enough stuff. thats only like 8 components to your nutrient mix. you need more stuff that conflicts with the other stuff and gets the ratios out of balance. ITS ABOUT BALANCE. [now repeat that out loud to yourself three times.]

you work for Advanced Nutrients or something??

last I checked it was a WEED and we all know it can grow from a clipping you tossed in the trash three weeks ago. It doesnt need some multi hundred dollar nutrient regiment. Water and a couple bottles is all ya need. The rest is just for show and tell.

 

[420blunts]

thanks for the info on da mini blocks lysol. and as for wait..what, i will NEVER give newly planted clones full strength feeds. i ain't that new to growing, just new to growing with rockwool. just been doing soil runs with sunshine mix 4 since i started last year. i do have & plan to use all AN components but don't add them this early and not all of them at one time. i start adding other stuff at the 3rd week of veg, around 700 ppm. i do have a feeding chart planned out. i just wasn't sure how often i should be watering rockwool. can't believe everything the local hydro guy say. gotta ask q's especially with this online community available. hey ourcee, thanks alot for your input. maybe i should really air cool my light to be able to drop my thou'e at the 2ft mark like yours. i've only grew indica dominant strains so far so stretching hasn't been an issue for me when i start the lights at 4ft for the first two weeks of veg. final decision i came up with about watering rockwool is i will water 6 babies everyday and the other 6 will get watering every 2 days. it's exciting to start this learning process again.

 

[koidr]

Try not to squeeze the blocks let the sit for 12 to 24 out of the water when you squeeze you lose the cap. for air in the block.I put my rooted clones in the 4'' blocks that were treted with 1/2 strenth 550ppm @5.8 2 days later i hit with full.buy the 6 day i have to put in 6'' roots popping. At least thats with my strain is indica dominant strains also. And i also use a 1000w mh no hood and i keep it only 2' off. This batch started at 5'' when i put in 4'' 6 days later 8'' into 6'' at 3 weeks plants at 18'' toped down to 15'' one week later at 19'' put into bud 12x12.Still through all only water every 2 days. I guess i am and old timer dont mind the hydro. but still think the plants needs to go through a dry cyc.and then through a wet one. I think this way the bud has a better punch to it. hope this helps

 

[420blunts]

thanks koidr for your input. i'm a believer with the wet & dry cycle. i would use to only water every 3 days when i did soil. soil would be pretty dry by then but my purple babies never flopped on me. just wasn't to sure if letting rw dry up a bit would be a smart thing to do.

 

[ourcee]

thanks koidr for your input. i'm a believer with the wet & dry cycle. i would use to only water every 3 days when i did soil. soil would be pretty dry by then but my purple babies never flopped on me. just wasn't to sure if letting rw dry up a bit would be a smart thing to do.

def allow it to dry.

I dont think its best to let rockwool get to a totally bone dry state. the minerals and salts will buildup inside the wool if its too long between waterings (sorta hard to do if youre really keeping an eye on it).

Rockwool is awesome because it can hold massive amounts of air within the block while still retaining lots of moisture. This is good too because you can run higher ambient temps (aka closer light) without worrying so much about root rot.

regarding the stretch and whatnot too. im not sure if your light is adjustable (hopefully) or there is a way to alter the height of the light mid grow basically. But yeah put em at 2 feet above and they will actually stretch less (especially if you are using a MH). There are some sativas that almost triple in size, and then theres some indicas that wont stretch at all... every strain is a little different so with those PK's you just gotta get a good feel. I've heard that the stretch isnt too bad on PK though, 1/2 its size or so? (dont quote me I'm not positive) I'll find out sooner than later though as I'm running it right now too

 

[420blunts]

hey ourcee. yeah i can definetly drop my lights. i actually just got done lowering them to about 26". did the hand under the lamp test again at that height and still didn't feel any discomfort. i ran pk for the past year in soil using hps to veg & flower and never had any problems with strectching. pk is just a bushy close node indica imo. grown properly will give you nice purple flowers with a really nice fruity smell. especially after you grind it up.

 

[Teratron]

or it could be that the plant has no need for 1500 ppm while it has a mere 4 fan leaves worth of vegetation

1500 ppm even in bloom is going to yield little to no benifit with most strains. I have a couple of hogs in my garden but even they will perform fine with less.

Much better to start on the low side and work your way up.

 

[420blunts]

hey thanks for your input teratron. the feeding schedule i have planned out has a max feed at 1350 ppm ( 150 ppm of tap water included) for week 4 & 5 on an 8 week bloom grow. i've never went past that amount on pk when i did them in soil.

 

[Teratron]

As long as you don't increase the ppm too fast and monitor for nute burn you will be fine.