DWC - Not working as expected.

[axilotl]

Hi all,

this is my first grow and I'm having serious issues. Advice is very welcome.
DWC in 2 single buckets.

Equipment:
Tent: Secret Jardin Hydro Shoot 120 (120x120x200 cm)
Bucket: Oxypot Single DWC (max 19L)
Seeds: White Widow x Big Bud 100% (feminized) (NON autoflowering)
Water: RO (30 ppm)
pH + EC Meter: Bluelab combo meter (Calibration confirmed)
Light: Mars Hydro SP 250 (Height above plants seen in setup picture below)
Ventilation: PK 125 EC-TC (max 680 m3/h)
Light Schedule: 18/6
Nutrients: General Hydroponics Tripart
Supplement: General Hydroponics Calcium Magnesium (added beginning 3rd week)
Additional Equipment: Small fan blowing lightly towards plants


Week 1 and Week 2:
Water in Bucket: 13.5L (which is about 2 cm below bottom of netpot) (= 3.6 gal)
FloraMicro (Soft Water): 14mL (= 2.8tsp)
FloraGro: 14mL
FloraBloom: 14mL
Resulting ppm: 550ppm (1.1 EC)
pH: 5.5 to 6.5 (adjustments were made)
Temperature tent AND water: between 22 C to 25 C (71F - 77F)
Water changed after Week 1, 2nd week parameters same as above.
Issues:

• Very slow growth
• Plant not growing in height
• Brown, rust like spots on leaves (not just tips)
• Leaves curling
• Leaves with spots dying

Week 3 (which ended today):
I thought maybe I gave too many nutrients, so I reduced those. Also thought they are lacking CalMag so added CalMag and tried to follow this:

Spoiler: Feed Schedule from growweedeasy

Water in Bucket: same as above
Calcium Magnesium Supplement: 10mL (=2tsp)
FloraMicro (Soft Water): 5mL (= 1tsp)
FloraGro: 5mL
FloraBloom: 5mL
Resulting ppm: 300ppm (0.6 EC)
pH: 5.5 to 6.5 (adjustments were made)
Temperature tent AND water: between 22 C to 25 C (71F - 77F)
Additionally: Yesterday (second last day of week 3) I saw a fungus gnat on a leaf, so added yellow sticky traps, and sprayed leaves with Neem Oil
Did not find anything on the yellow traps, roots looked clean visually.

Spoiler: Setup

Spoiler: End of Week 3 Roots

• No slime or smell

Spoiler: Close up - Problems

Known Issue:

• High water reservoir temperature

Troubleshooting performed:

• Added 0.5L frozen bottles inside, however temperature barely dropped 2 degrees Celsius for a short while
  • Cannot afford Water Chiller
  • Purchased fridge, but haven't managed to make copper coils
• Since growth is slow, I am not yet going into flowering light schedule!

Please Assist:

Please provide feedback. This is my first grow and I have no clue what's going on.

1. Do I even need CalMag supplement when using TriPart FloraMicro specifically for soft water ?
2. Are ppm's way too low now?
3. Were ppm's too high in first 2 weeks?
4. Is the lamp height acceptable ?
5. Could the water temperature alone be causing the leaf problems and slow growth ?
6. Suggestions ? Can this be saved?

Thanks!!

 

[GreatWhiteShart]

Looks like cal mag, gotta have it with r/0, also over aerate your buckets. The warmer the water gets the less dissolved o2 it can hold. My rez hits 76 during the day, but i run a stupid ammout of air stones, looks like my rez is boiling .

 

[Dirtbag]

Your light is less than ideal for starters.. and your ppm should be double what it is. I'd aim for 1.2-1.3ec 600-700ppm.
I also didnt see any mention of Relative humidity readings.

 

[Nate_in_AK]

Nice formatting, and welcome to the farm!! ✌

It looks like your have that fan blowing directly on the left plant; if so move it away. You want indirect air-flow; too much wind will piss them off.
Get some anti-fungal additive for your water and you'll be OK at those temps.
Are you aware neem oil makes your plants photosensitive, and needs to be added right before lights-out?

P.S. - your light may be less than ideal, but I'm fairly certain it is not part of your current problem.

 

[Dirtbag]

Nice formatting, and welcome to the farm!! ✌

It looks like your have that fan blowing directly on the left plant; if so move it away. You want indirect air-flow; too much wind will piss them off.
Get some anti-fungal additive for your water and you'll be OK at those temps.
Are you aware neem oil makes your plants photosensitive, and needs to be added right before lights-out?

P.S. - your light may be less than ideal, but I'm fairly certain it is not part of your current problem.

Agree with the fan issue, and I also dont think the crappy light has anything to do with the slow growth but figured I'd mention it lol. Issues with the light wont become apparent until mid to late flower...
I think it's the 300ppm feed. You need to push harder than that in hydro.

 

[axilotl]

Thanks for all the replies!

Feed: I've increased the feed to 500ppm.
Neem Oil: Unfortunately I didn't know that it has to be sprayed during lights-out! Will keep that in mind for the future.
Humidity: Between 50 and 65%.
Anti-fungal: We don't have Hydroguard here in Europe, I will try to find an alternative. Suggestions ?
Fan: Has been moved away.

Light: Why is it not ideal for starters? Will this whole project fail based on the particular light choice ?

Thanks again all, for taking the time!

 

[GreatWhiteShart]

Hey man,
Your light is fine, the sp series is used alot in commercial grows. The only down side is the small flower width. Mostly people use multiple units, but as long as you want to flower a 1.5 foot wide area you good.
With most mars hydro stuff, use it at 50% of recommendations.
I use black dog and mars too. Honestly, there is such a small difference between the two......it makes me sick
Dirtbag is using hps/mh, but not everyone can hide that heat so led is what we get.
Just invest in learning to grow and then upgrade as you learn
You will get some great tomatoes

 

[PhatNuggz]

DWC has serious issue/obstacles, heat being just one

Reconfigure to an outboard rez, which allows you to swap out cold packs, adjust pH/ppm and watch/adjust level

hth

 

[axilotl]

I was thinking about doing that, with an external reservoir. It just adds to the complexity (in my opinion), and makes it difficult to clean. Every week I empty the buckets and scrub them out in the bathtub. Which might be overkill, but with pumps sitting at the bottom of a reservoir, and not being able to draw every last drop out, I imagine, cleaning/flushing becomes difficult.

To prevent root rot, due to higher temperatures I did purchase a product today.
Since Hydroguard isn't available here, I bought this: TNC MycorrHydro
I hope it will serve me well.

 

[Deadstill]

Save time, money, and headaches. Go buy Clorox Bleach (make sure it is regular Clorox bleach, not the scented, and definitely not the "splash-less" crap.)

Anyway, read the side of the bottle and make sure it contains at least 5% Sodium Hypochlorite and preferably nothing else.

https://www.amazon.com/Clorox-Regul...clorox+bleach+original&qid=1598124290&sr=8-11

This stuff is about 6%. Use 1ml of bleach per 1 gallon of reservoir water every time you change your water and forget about it. You may go as high as 3ml per gallon if you have really bad root rot, to treat it quickly. This may cause your plants to wilt for an hour or two at a higher strength, but they always recover and will LOVE you for it.

 

[axilotl]

We don't get Clorox here, but DanKlorix:

Only 2.8% Sodium Hypochlorite. Others have perfumes. I think its some EU regulation, to keep it below 5% ?!

Any thoughts about this one ?:

Amazon.co.uk

 

[axilotl]

pH instability issue!
This happened now 3 days in a row. Before lights off, pH in both plants is 6.0. In the morning, 12 hours later, I check when I wake up:
Small plant pH: 5.4
Larger plant pH: 4.6
Water level in both plants dropped very mildly. Maybe 100mL
Nutrients dropped maybe 20 ppm

Any ideas whats going on?
As per this chart below, its acid rain issue?!

Spoiler: Chart

 

[axilotl]

Just to clear the confusion: I meant after 12 hours pass, and I check when I wake up, but the cycle is still 18/6.

 

[axilotl]

So at 8AM, I pH'ed the larger plant back up to 6.1
Now 9 hours later, I checked again, pH dropped to 5.1
During this period, nutrients dropped slightly from 390ppm to 360ppm. Water only dropped around 100mL.
Any ideas whats going on?!

 

[axilotl]

This is interesting regarding pH drifts:

 

[Deadstill]

Hey I am sorry I haven't replied lately I have been SO busy.

Yeah I would say if you can't find clorox, use a similar brand of bleach. If all you can get is 2% sodium hypochlorite then just simply double my recommendations for adding to your reservoir. So with 2% I would go like 2 ml bleach per gallon of water, no more than about 5 or 6 ml per gallon max.

Pool shock works, too as long as it's just sodium hypochlorite and no other active ingredients.

You can even go for food grade Hydrogen Peroxide but it's not as cheap as bleach.

So, the pH swings are in direct relationship to your plant's uptake. Generally with hydroponics you know you've got a problem when pH goes anywhere BUT back to 7.0. So, let's say you add water/nutes to your res. and the PPMs are 500 and the pH is 5.8. If the next day, you go test your pH and PPMs, you should get different results than what you had yesterday.

Let's say the PPMs went down to 450 and the pH went up to 6.3, and the water level dropped by, let's say, half an inch. This tells me everything is going well.
This tells me the plants are eating (ppms dropped and pH rose back towards the 7.0 mark) As the plants eat the PPMs will drop and the pH will rise because those nutrients that were causing the pH to be lower than 7, are being used up and removed by the plants. 100% pure water (0ppms) should always be approximately pH 7.

Now, if you go check your res the next day, and the pH has DROPPED, or moved away from 7.0 instead of towards it, then you know there's a problem. If the PPMs are dropping and pH is going down, water level going down, and plants look like shit, then you've almost certainly got root rot, or some sort of LOCKOUT.

Here is a simple little chart I've found here that helps explain the relationship of PPMs to pH and water level in hydroponics.

^^^ When they say EC they also mean PPMs (just different units of measurement)

So it sounds to me like what you're experiencing is a direct result of root rot and/or some sort of pathogen/fungi/bacteria/algae are causing lockout in your plants. To be totally honest I have never found ANY beneficial bacteria that will cure a bad case of root rot. I've used Hydroguard and such for *prevention* but never worked for me to cure infections. Best bet is to just run a sterile res. and have way less headaches. Especially once you move on to a bigger scale, we can't afford to waste time money and effort on a "maybe".. I sleep easier at night with a sterile reservoir..

I hope this helps and wish you the best of luck!

 

[KingJames]

I poured a capful of bleach into my res yesterday, just because I thought I smelled something (I think I was wrong actually and it was just me that smelt LOL) but smelt nothing in the reservoir today.

Plants didn't seem to complain either. That said, mine don't even have roots near the water yet. :S

 

[axilotl]

NEW PROBLEMS!​

Hi all,
thanks for all the support. So I extended the Veg a little bit and am now flowering since 1 week. I encountered the problem as shown in the picture below.
I am still following the nutrient schedule from my first post above. 1,1,1,1/2 (ppm around 800). Roots still look good. New growth, no rot signs.

Some of the leaves are getting these brown spots!! It's on both plants. Maybe 6-7 leaves had it.
Sprayed Neem Oil on them, not knowing if its bugs. But I definitely don't see any bugs. Cut off all the affected leaves.
Now 2 days later, after the Neem spraying, I see a few new spots appearing on other leaves.
Only thing new is, I've pruned my crops quite a bit.
Any ideas what these spots are?

Spoiler: Pics

 

[axilotl]

Bad job on maintenance. Update at the end of Week 5 of flowering. Nothing really big.
How long more to go ?

 

[Kampbe1l]

that question again....

i reckon its only about half way thru its flowering phase, most of its pistils are still white. patience, as last 2 weeks before harvest is when some strains fattens significantly.

i estimate such timetables, but in the end, its the plants which should dictate when.