Newb needs some advice

[Scaryshark]

Hi all,

I just started a dwc grow in a homemade sytem using a 10 gallon rubbermaid container and five, 5" cups, that will be converted to full Deep Water Culture as soon as my water pump and irrigation hub get here.

Anyway, here is some background and then my question...

I started 5 Durban poison seeds in rockwool in the cups with hydroton surrounding the rock wool. I used tap water that wasn't ph'ed since I didn't have the proper meter yet. The tap water was just up to the bottom of the cups with plenty of bubbles to splash things around and keep the hydroton wet. All 5 seeds were up in two days and are on their 4th day today. They all look healthy with one slightly behind the others.

Yesterday I got my ph meter and tested the tap water first. It was around 7.8. Obviously way to high. I drained and rinsed the container and filled it with 4 gallons of water. I plugged the airstones back in and added ph down directly to the container (with the plants resting in another container), I got the ph down to around 6.7 and then added a very, very light dose (just a few drops really) of Flora Nova Bloom. Just enough to raise my ppm from 270 right out of the tap to 335 and checked the ph again. It was right at 7.0 which I figured was enough of a drop at one time. I then used some of the new ph'ed water to wet down the pots from the top while they were still in the spare container (which was clean), I tested the runoff from the cups and the ph was around 7.3. That seemed reasonable to me given the high ph of rockwool. So I put the plants back on the freshly filled container and buttoned everything back up.

I went back several hours later thinking I could maybe drop the ph a little more to get closer to ideal. When I looked in the tank the water seemed cloudy and when I tested the ph it was up over 8! The ppm had also dropped to about what the tap water is naturally. I removed some of the water from the tank and added a little ph down. I added this back to the tank and checked the ph again. It was now 6.7 and the water was clear again with some whitish residue on the bottom of the tank.

Any ideas why the ph is jumping around so much and what caused the water to be milky looking when it was clear as a bell after I finished the initial drain and refill?

Thanks, SS

P.S. One of the plants has it's taproot to the bottom of a 5" pot after less than 2 1/2 days from popping it's head up!

 

[BloodShotEyes]

Did you rinse the rockwool and hydroton with phed water before you put it in the system? That might have something to do with the cloudy water and your ph problem.

 

[YardDog35]

Welcome! You are in the right spot!

I agree with bloodshot. Hydroton needs to be rinsed with ph'd water about a thousand times...well not literally, but you get the idea. I rinse/clean mine with tap. Once the water is clear coming off the clay I rinse with ph'd water again and again. Finally give them a good soaking in ph'd water.

With that being said, what's done is done and it's no big deal. Most new DWC and Deep Water Culture systems raise the ph for the first week or so. It all goes back to the hydroton. I just started mine and ph'd it at 5.8, 2 days later it was at 6.7, again not a big deal.

I can tell by your post you have done your research and are ready to be successful! I caution using any nutes at this point...but you only raised the ppm slightly, just be careful cause the little ones that need to catch up could get burned.

Last but not least, was that a typo when you said you fed it Nova Bloom? Or do you know something I don't?

Oh-and the milky water is from the nutes you gave it.

Good luck with everything!

 

[Scaryshark]

Did you rinse the rockwool and hydroton with phed water before you put it in the system? That might have something to do with the cloudy water and your ph problem.

I did rinse the hydroton but I didn't soak it in ph'ed water. I did soak the rockwool in water that I guesstimated to be around ph 5.5 (at the time I didn't have an accurate ph meter), I later found that it was closer to ph 7.

Welcome! You are in the right spot!

I agree with bloodshot. Hydroton needs to be rinsed with ph'd water about a thousand times...well not literally, but you get the idea. I rinse/clean mine with tap. Once the water is clear coming off the clay I rinse with ph'd water again and again. Finally give them a good soaking in ph'd water.

With that being said, what's done is done and it's no big deal. Most new DWC and Deep Water Culture systems raise the ph for the first week or so. It all goes back to the hydroton. I just started mine and ph'd it at 5.8, 2 days later it was at 6.7, again not a big deal.

I can tell by your post you have done your research and are ready to be successful! I caution using any nutes at this point...but you only raised the ppm slightly, just be careful cause the little ones that need to catch up could get burned.

Last but not least, was that a typo when you said you fed it Nova Bloom? Or do you know something I don't?

Oh-and the milky water is from the nutes you gave it.

Good luck with everything!

I believe that the ph variance is due to the rockwool and/or hydroton having an alkiline ph. I ph'ed the water again tonight and it was still in the high 6's when I started. I went a little to far with the ph down and had to come back up, when I got it to 5.8 I left it and checked it twice since then. After 2 hours it was up to 6.3 and 2 hours after that it was 6.4, so I think it is starting to settle down.

The reason I used bloom ferts initially is because I have read that in the seedling stage the plant needs more P to grow roots and little N. You know, like a bloom fert provides. I will be sure not to over fertilize. I don't plan on using more than 1/4 to 1/2 teaspoon in 4 gallons until the plants get some serious veg going. That's about 1/16 to 1/8 strength. The Flora Nova should also help stabilize the ph from what I have read.

Thanks for the responses! SS

 

[YardDog35]

you have it all under control my friend!

Interesting theory on the feeding. As long as it is very small doses that makes sense. I just like to play things on the safe side. Then again I don't have a ppm meter...


Keep us posted!

 

[Scaryshark]

you have it all under control my friend!

Interesting theory on the feeding. As long as it is very small doses that makes sense. I just like to play things on the safe side. Then again I don't have a ppm meter...


Keep us posted!

I hope I have it all under control, LOL!

I cost myself about 3 weeks of growth by overwatering the plants I have growing in Sunshine soil-less mix, even though I knew that the first thing rookies do is overwater. It is amazing to me how dry the soil (or soil-less mix) can get without harming a marijuana plant. Damn things seem to grow like weeds! Well, at least until you are in charge of everything they eat and live in. Then it seems to get a little more complicated...

I will keep everyone posted.

 

[BloodShotEyes]

Lol, Grow like weeds, They are weeds, Your Ph problem should calm down in a few days unless there is something else wrong which I doubt, You did your homework from what I can tell.

When ever I start a new grow it takes a few days for the ph levels to set in. I just have to keep a eye on it.

 

[Scaryshark]

Thanks for the replies everyone.

My little guys and gals are looking great. The PH has stabilized. I drop it down to 5.7 or so and it rises to 6.5 or so in 24 hours. To me that seems about perfect.

I bought a second container so that I could switch between the two when I wanted to do a complete drain and fill, but I have found that it is very convenient to set the lid with the plants in it on top of the dry, spare container when I am doing maintenance on the main container. I remember Roseman saying that his plants responded to this air bath. Well I swear to god my 5 day old seedlings doubled in size about 5 hours after they had 30 minutes of exposure to air!

All 5 of these plants are Durban Poison and I can't wait to see how they respond to a 12/12 cycle from seed. My plants in soiless mix are showing sex and I had one Durban female and one mystery seed female out of the 5 plants that grew healthy. I already am getting impatient!!

 

[Hydrogrown]

using H2O2 or hydrozyme with the res. change will help keep the ph stable too, and prevent unwanted growth in the res. but your plants should be flowering by now, good luck!