So I have only 2 plants in my 18 gallon tub, and I was wondering how long I can go w/o changing the water. It's kind of why I'm only growing 2 plants, because I get my water from those vending machine things that fill 5 gallon jugs (my tap is about 400ppm and 8-8.5 pH).

Also, should I bump the ppm higher? I'm just super worried about nute burn again, my plants have already had a traumatic enough childhood, and with 1 each sativa/indica worried about the WW getting burned while the church takes it like a champ.

About my grow- 1 is Greenhouse Church, other WW. I procrastinate REALLY bad, (these were just in cubes in styrofoam cups under cfl's for about 2 weeks at least, and the church had about 12" long roots before I even put it into the tub) before I ripped out my first test plants and restarted (they were bag seed and i really wanted to put these puppies in).

Right now, water is about 189ppm, 5.6pH, and these guys are loving it. My first grow I would repeatedly nute burn my plants and they'd get better, and i'd do it again (grrrrr!) so I'm going slow. Roseman's/purpledaddy or something like that thread has helped a LOT, especially for the ppm for each stage. The pictures I have are the difference from when I was at 100ppm and bumped to just under 200 over 2 days. Before that, the sativa's leaves I trimmed cause they were burned (I'm still not sure if that was right to do), as in the tips. I trimmed the dead bottom leaves on them both.

The light (400w MH conversion bulb) is about 11.5" above the top of the water container, and I think that's a bit high but i just think if it gets any closer the plants will start to burn (from heat). I have a 340cfm fan in a 3.2'x3.2'x6.6' room, but since it's literally in a closet I worry about ventilation. I have a circulating fan that I hung upside down that circulates air mid level, and a small 6" table fan on the ground to try and circulate the cool air on the bottom. The temperature in the room tends to sit on the high end between 80 and 90 degrees.

Above all, the bright green these guys turned into from the pale, burned tips that they were is exciting as hell.

I know that's a lot to read for a 2 plant grow, but it still makes my pants tight thinking about harvest =)

Attached Images

	baby1.jpg (31.6 KB, 21 views)
	baby2.jpg (67.7 KB, 27 views)
	baby3.jpg (53.3 KB, 20 views)
	baby4.jpg (98.9 KB, 23 views)

whats the temp of your res?

also i'd try bring down your room temps to 70's

i wouldn't go more than 2-3 weeks without changing.

__________________
http://www.rollitup.org/grow-journal...aze-hydro.html

What is the deciding factor in how long before you change?

I'm not sure of my res. temp because I don't have a thermometer for the rez (only a digital in/out that had the "out" sensor tore up when it hit a fan blade). With all the reading I'd done before hand, I didn't see much talking about rez temps, but in my posts people have asked again and again. What is the proper temp? Mine is cool, guessing between 70-80 degrees based on external temperature.

I have to wait until my apartments fix my A/C, but since the apartment temp right now is just under 80, I think when it's fixed it should be able to bring the temp at least to between 70-80 (i hope). During the day I have one of those tower fans blowing air into the closet from the room so it has cooler air to circulate.

I usually keep my tent zipper open half way since it creates such a vacuum and I don't want to burn the fan motor out. Am i being overly cautious or is that a real issue?

hi ob i normaly change my rez once i have added the same amount of water as is already in ie 20ltr rez say your plants drink 3 litres a day i would change after 7 days as ive added 21 litres of water.as for rez temps i keep mine at 64f to 66f any higher than 70f and you run the risk of root rot.hope this helps lol ph1l1p72

AHHHH root rot, thats why water temp needs to be lower. Been looking for the answer to that question for a bit, tyvm!

It looks to me like the leaves in the last pic are curling up. These is a post here that will tell ya what that means, sorry i'm to new to this to have it memorized yet!

Also I know all strains are different, but I use Fox Farm nutes and I can safely start the ppm at about 500 (After 2 weeks) and thats with a start of 30 ppm. Ive actually got a 2 week clone in a 1850 ppm flowering tub and its getting its groove on so far. I also use superthrive and I don't know if this helps my seedlings and clones, but a few drops per gallon is cheap and seems to lessen shock??

Also FoxFarm makes Grow Big and Grow Big Hydro. I mistakenly bought the regular and have been using the reccommended doses for it with little issues. When I finnish up the regular ill move to the hydro to see if there is any difference.

More stuff you already know: Mix all your nutes in one container with water and just add that till u get the right nutes. I was adding a little of each to feed my tanks and it was never right. Now i can hit watever ppm i like within say 10-20 ppm.

so when a switch from veg to flower do u slowly bring upto 1000 odds ppm from 4 500ppm or do ya fire it right upto 1000 odds ppm as soon as u switch to flowering noob with all this ppm testin i no wat it is justnotsure how to apply it dont wanna kill the fem seeds them fuckers be dear any help b nice