My 1st personal CFL grow cabinet ~

Hi all, This is my first try on growing. I could use any advices from you all.
Thx in advance.

The cabinet was custom made. One exhaust fan on the top + one fan for air circulation.
I'm using CFL bulbs with vary brands. I just bought one bulb branding " bio-bulb". It says that this bulb would produce more than 3million negative ion, which i've read that it is good for the plant.

** I have trouble adjusting my pH level. I use the drop test method to measure pH and it seems inaccurate to me.
Every time I put the pH down acid in the water solution and try to measure the pH. It always go way too down.
Wondering how much of those pH down acid should I put in, or should I wait for more longer time before I measure the pH again. **

again, I'm looking forward to advices from you all.

1ST WEEK

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I'm confused. Are you growing in just rockwool ?

I believe PH down comes with a pipette, I'm assuming you're using that for dosing your water. If not, get a pipette. $6 for 100 off amazon. Another alternative I've seen used is empty drop bottles (think eye drop bottles, but they have larger ones with tops you can unscrew to refill em). If using eye drop bottle, just dip it in the pH down and squeeze it so it'll suck into the bottle.

If you have a large body of water/nutes, be sure to mix the PH Down well so that you can get reliable reading. If you're not mixing it, you're waiting for it to diffuse through the body of water and that will take a while and so you'll need to put some drops in, wait 30 min or so, and check again.

What I like to do is put a couple drops in while the air pumps/airstone are bubbling my nutrient mix. It does the mixing for you. Another alternative is to use a water pump to do the mixing. The non-lazy way is to stir it up.

Also, keep in mind that if you're adjusting pH on a nutrient mix, you'll need more drops. If you're adjusting plain ol' water, you'll need less. After a while, at least for me with the pipette, I just know I need about 1.5-2mL to drop the pH from tap water's 7.5 to around 5.8 for 3.5 gallons. This comes in handy when I have to top off the reservoir with just plain water.

Well nute mix is usually lower ph than just water, why would it need more drops?

Depends on your nutes + additives. For example, my personal feeding regimen is a bit of extra calmag followed by Protekt (silcone), which raises the pH, and then by the appropriate amount of nutes (determined by EC). Say for seedlings 15 days from sprouting. I'm not gonna bombard them with nutes and so the amount of nutes given isn't enough to lower the pH to the right range.

Also, another example I've experienced, the Maxigro line of nutes from GH doesn't lower pH as much as the Maxibloom nutes. So with Maxigro I usually had to add some pH down after everything was mixed to the right levels. With maxibloom @ 7g/gallon (including the calmag and protekt), I end up at 5.8 dead on everytime and so there is no need to adjust once the plants can handle the 7g/gal dosage.

TLDR; Nutes don't always drop the water pH to the right range (or below it). It depends on nutrients, initial water pH, any additives being used that impact pH, and feeding dosages.

Thx quisqueyano, seems like I drop too many acid so it goes way down. The bucket I'm using contain 10.5Liter/2.8Gallon of solution water, suppose I only should put only 1-2ml for that.
and yes dc4, I'm using rockwool and solution water beneath it. + airpump

2nd WEEK


They are growing real fast with the negative ion generator i put in. but Why the new fan leaves are really big; it block the light for smaller leave beneath. Any PROs suggestion?
I'm still deciding between LST and SCROG

Another problem is that the tip of the leaves are yellow, whats wrong? see that in picture 3

4th WEEK
A lot of shit happen last two weeks,
I did some FIM cut and some scrog. Also I added the co2 bottle, grow real fast !



Do you guys think I should switch to 12/12 now? or wait a little more until the screen is fill.

I would flip ASAP.... it will start to pack out in no time

Thx i'll do it tonight

When do I must change the bulb to 2700K. Right after I flip to 12/12 or what?

Thx lots if u reply

A light bulb that produces light perceived as yellowish white will have a color temperature of around 2700K

I know but "when" do I change from White Bulb to Yellow Bulb?
right after I filp the timer to 12/12 or wait until i see some flower.