Thanks for the info and the links @Ralf. I’ll read them as soon as I get a little time later.
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Do deep water culture.
My only waste is a neoprene puck now
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What brand rockwool are you going to use, I’m currently using the grodan slabs but I need to use slabs that are pre cut at my micro, I know Redrock has them but I’m not sure the difference in between them and grodan.
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For sure, are you running RDWC? What are you using for waste destruction diluant(s)? Or are you composting?
I used RDWC in the past. It’s an excellent method. Especially when injecting O2 nanobubbles to get DO2 in the 15-20 ppm range with water temp in the low 70’F range - probably the fastest growing and best yielding system I’ve ever seen. Plus, it helps prevent root disease. I’m unaware of anyone injecting O2 nanobubbles for RDWC or DWC, but I’m sure someone is doing it. DM me if you want to discuss. 
For us, DWC or RDWC wouldn’t work because I’m going to run high plant density (1 plant/SF at most) in single and multitier rooms to get six harvests per year per room.
Plus, for RDWC, I am too concerned about whole crop infection, same goes for ebb/flow, NFT, high-pressure aeroponics (HPA), and (insert recirculation method here). We could use UV and chemical sanitizers, but they aren’t 100%. I wouldn’t sleep well with nightmares of hundreds of plants, all with root rot - something I’ve seen with RDWC in a consult I did years ago.
If I could choose any system for the best plant growth, root health, etc., it would be RDWC injecting O2 nanobubbles (15-20 ppm DO2) with HPA nozzles above the water (with O2 nanobubble injection). While HPA with O2 nanobubbles would probably be better than that hybrid system, I would worry too much about dead pumps leading to dead plants.
I’m using O2 nanobubble injection into my batch tanks for each room with a sizeable O2 generator skid to achieve 15-20 ppm DO2 at the drippers. And after reading exciting and surprising new research on CO2 injection (DCO2) on photosynthetic rate, carbon fixation, growth rate, and yield, I plan to test a 95:5 O2:CO2 gas tank mixture.
I’m planning to use Grodan’s newish Grow Block Improved line. But, when they release their new Max line in the US, I plan to switch. The Grow Block Improved line offers improved air porosity, less channeling, more uniform wetting, and better dry back control. The new Max line offers the same benefits but uses a sugar-based ‘green’ binder for the fibers.
For dry back control and to maximize irrigation events per day (and therefore increase growth rate), I’m using blocks, not slabs. For my plant size (max 2-ish feet tall), I’m using ~2.73 L total substrate volume per plant as GBI GR4 (3"x3"x2.5") for veg to fill the cube quicker (veg is ~2 weeks) and GR22.5 (6"x6"x4) for flowering. I’m stacking the GR4 on top of the GR22.5 for flowering, with three 0.5 GPH Netafim psi-compensating drippers per plant. One dripper in the GR4 block and two in the GR22.5 block - all on the upward slope side of the blocks. Flowering will be drip using Acclima VWC sensors from Growlink (calibrated with Grodan’s new 5-prong VWC sensors) to automate irrigation events. Veg will be timer-based ebb/flow.
I don’t know much about RedRock rockwool, except their Pro line seems to be a white-labeled version of VidaWool from Owens Corning. From the VidaWool/RedRed Pro marketing, I like features like the light-blocking plastic wrap and round clone cores. I am considering using VidaWool instead of Grodan. But I first need to send a bunch of questions to VidaWool (w/r/t air porosity, pH, etc.). I like the price point for VidaWool vs. Grodan.
Another option is Cultiline; their RootmaXX blocks look interesting. But I don’t know if they have reliable US distribution, and I assume the cost would be a factor.
If I were to use VidaWool (i.e., RedRock Pro), I would use their Block 40 (4"x4"x2.5") for veg and Block 144 (6"x6"x4") for flowering; providing ~3 L of substrate per plant. I would stack the Block 40 on top of the Block 60.
- VidaWool Block 40 = RedRock Start Block Pro 42/40
- VidaWool Block 144 = RedRock Grow Block Pro 42/40
RedRock’s ‘solo rectangle grow slabs’ are interesting, but I don’t think they’re available in the Pro line.
I’m ordering their round clone cores to see if they fit inside Grodan blocks. If they, I’ll use them instead of Grodan A-OK 1.5" cubes.
One thing that concerns me a little is their pH. Because, unlike Grodan’s GBI blocks which have very little carbonate (neutral pH), @emdub27 wrote the RedRock block has high pH. However, I’m not sure if he was referring to the Pro line or the standard RedRock rockwool (I suspect the latter). The Grodan rep told me we no longer need to acidify the pre-soak water (to neutralize the carbonates) because their mfg process now reduces the carbonates significantly.
But high carbonate in rockwool isn’t a huge issue. All we need to do is acidify the pre-soak solution. I would test the effect of a range of pre-soak solution pH values on the substrate pH (Pour Through and SME) to identify the ideal pH to neutralize the carbonates significantly. I hope VitalWool already did that testing and can suggest a perfect soak pH.
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The RedRock slabs aren’t available in the Pro line. Getting a proper soak for wrapped slabs seems problematic. It looks like their standard line doesn’t offer all the benefits found in their Pro line (i.e., VidaWool) or the Grodan GBI line. Overall, I’m not a fan of slabs. Why not use blocks?
EDIT:
According to RedRock, their slabs are the ProLine, see:
I used 6x6x6 for veg and flower, and without the transplant at flip it doesn’t work as good. I’ve been using 4x4x2.5 for veg then stack on a slab at flip.
To saturate the slabs it’s easier for me, I just stick my drippers in it and fill them, let it soak overnight then poke a hole halfway up the next day, then after the initial dry back I cut the whole end open.
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The pro and standard Red Rock I’ve received are all identical material including the slabs. It performs like the old white wrapper, green writing Grodan. I’m the one weirdo that hates the improved Grodan, I noticed way too much inconsistency in block density and therfore water water capacity a couple years ago and haven’t used it since.
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ralf where would be the ideal placement for the acclima sensor in a grodan meter long slab with three 4x4x2.5 cubes on?.
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shit, i just soaked mine overnight then chopped the end off?, didnt know you were meant to just poke a hole in half way up then leave till after the initial dry back.
is the idea that with the hole half way up you just lower the water table so to speak so the top off the slab thats in contact with the cubes can dry back a bit to encourage roots to explore without the slab getting to dry to quick?.
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This is how I’ve been doing it, not sure if it’s right or not but it’s been working ok for me. Grodan Instruction Video #2 Creating Drainholes with pre drain - YouTube
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Did you ever end up getting an Aroya media sensor? I’ve been following them for some time now and have been really interested in giving them a try.
FWIW, I looked into this topic:
RedRock is white labeled VidaWool. The Pro and standard versions are not the same; they have different fiber densities and binders, etc. They don’t sell the standard anymore because it had less density and water holding capacity (IIRC). So it could be that they are still referring to the standard as the standard even though it’s the Pro (which is how their website lists their products). They said it was comparable to the Pargro blocks from Grodan, IIRC. All blocks and slabs are now the Pro version.
Grodan started selling the GBI blocks around 2020. Here’s the product line progression:
- original (I’m not sure what it was called) > Pargro & Delta (concurrently) > GBI > Max
From our Grodan rep:
Off the top of my head I’m going to say Jan 2020. It was a pretty slow rollout because our distributors were well stocked on Silver wrapped “Delta” wool, plus that’s what the market had long used, so the transition took the better part of 18 months.
There was also the Pargro line that was similar to delta (same wetting agent/binder) just a bit less dense. Delta was around for many moons, then came GBI, and Max is next in line. Max is currently available in Europe, but not yet in the US. All indications are that it will be released, however, the how and when are in question. What will likely happen, once we have a confirmed launch date, is that trial product will be made available. If you’re interested in trialing the MAX we can put that together down the line.
I’m not sure; I don’t use slabs. But you can reach out to Grodan and ask them. I know you don’t want the sensors at the very bottom because the moisture content is greatest at the bottom.
Just thinking off the cuff, if it were me, I might install two sensors in two of the three blocks and one or two in the slab. For our grow, we’re using four sensors per zone, with an average of those sensors used to automate irrigation. But I may increase it to six after uniformity testing.
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Has anyone just tried to use Hydrobuddy and trust the labels as being correct? Is there any reason to believe there is anything in the bags that isn’t on the label or SDS? I see concern about the pH being in the 4 range and it shouldn’t be, but is that the only evidence? I admit to being naive on fertilizer label rules, but can they have ingredients in there that aren’t on the label? If it had Pekacid in it woudln’t the sds have to say Potassium pentahydrogen bis(phosphate) or phosphoric acid, potassium salt? My Hydrobuddy calculations come out pretty correct and as expected when you add the masses up. I don’t want the solution to be 4 and the pH seemed perfect using the clone recipe and my soft (100 ppm) tap.
I’ve had Athena Bloom + Core solution analyzed by a lab and it was close to the label values, the major difference is that the Mg is higher in reality than the low values on the label suggest. K tested lower, P a little higher. I just made the clone using the usual culprits, MKP, SOP etc. according to the label values, since I didn’t have the test results back yet. This was back in 2020, I did one run like this and it turned out pretty great, average THC for the strains was 20% and terps were 2%. And these weren’t high thc strains, just normal stuff. Big Bud came out at 25.4% haha. The yield was 0.9 GPW and I grew using DE HPS. A later run with genuine Athena tested a little worse in thc and terps, although there were other variables different between the two runs. But it suggests that the clone isn’t way off. I do think the smells and frost were superior in the genuine Athena product. I don’t have an explanation for why that might be though. I used the Plant Prod chelated micros, so there were some small differences vs. the Athena product. I got the test results back and cloned the Athena again using the macro values with more Mg, etc. and I didn’t like the smell as much as the one I made using the label values haha. Seemed more sour instead of sweet. For me, the smells are everything.
I was only running an input EC of ~1.7 (runoff of about 2.6) and unfortunately with sucanat sugar, which after many trials I can say seems to only have detrimental effects. I’m excited to try again at higher EC of 3.0 (and without sugar!) like they recommend, although I do grow in peatlite (sunshine mix #4). Has anyone tried a 3.0 EC input in peatlite? I’ve asked multiple Athena reps and they said do 3.0 in peatlite. But you never know…I don’t want to regretfully look at burned tips and leaf margins for 10 weeks. With Jacks I can’t even get to EC 2.0 without burned tips in my room. I do think the plants were hungry and needed higher EC when I used the genuine Athena product though.
I don’t even know why I want to clone it, but I chafe at $140 a bag, especially for the Calcium Nitrate part. In the grand scheme of things, even the Athena ferts are probably one of the cheapest expenses we have. If my math is right, Athena is 7.3 cents per gallon and my clone is 2.2 cents per gallon. I guess that’s why we are all in this thread though, the thrill of figuring out how it works and not wasting money. But I don’t want to miss out on any quality vs. just buying the real thing.
My notes from the Athena run are-
“Frost and sticky and smell is great, trimmers prefers to trim this type, almost no mold, trimming finished rapidly. Buds are very colorful and have enhanced bag appeal and aroma vs. Jacks 321. Buds seem less dense than Jacks 321. Honestly if I had to classify the smells from the Athena run they would be perfect.”
Medicine.grower thanks for all your pics, you are killing it!
This is a novel, I’m sorry. I just love thinking and talking about fertilizer.
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@emdub27 @Medicine.grower
Hey guys. Interested in popping something in here and please don’t feel some type of way to tell me I’m wrong. Something I noticed when plugging numbers into hydrobuddy and looking thru different line cleaning products. To cut to the chase, basically, I noticed that on testing for @Medicine.grower 55 gallons the sulphate tested at >400 where the closest I can get with hydrobuddy is 190 or there abouts with potassium sulphate and magnesium sulphate. So I started thinking maybe they were using some sort of sulphuric acid product.
To be completely transparent I’ve never dealt with pekacid or Haifa grow clean but I hear good things about descaling and bad about ph fluctuations, I’ve been in a 6 lighter trap with living soil and just did my first few runs at home with Athena(had to hop on the hype train) I’ve been running irrigation with a Ecowitt and aroya teros sensor having great success on yield and taste. But I’ve had issues of lockout at lower ec. Huge ph swings in the runoff I think due to nitrogen use efficiency, idrk tbh. it’s a clean nutrient that I can control however I don’t want to be running a 3.0 ec and 30%+ runoff every cycle.
To get back to it after my life story lmao.
I was looking at sodium bisulfate/bisulphite at maybe a cleaner they are using. By weight someone on rollit up forum said it was 30% less nutrients when plugged into grow buddy. I found 17% difference nutrient salts/ and total weight of the prill when I plugged it in, which is still a fair amount of difference( I also just used the default setting hydrobuddy gives for substances). This might be the answer for the extra sodium and sulphate but I still think >400ppm is crazy. And yes sodium bisulfate is a pool cleaner or stabilizer, I was also reading how it stays more stable at a higher ph but it’s ph is ~3.0 which could be what’s bringing the ph down in the final solution.
I really don’t know just something that no one brought up that I noticed at first sight. Most of this sodium bisulfate info is from google so feel free to roast me if I’m super wrong, also this is my first post on the forum so don’t feel discouraged to tell me that this was a ramble, just a 20 year old grower tryna learn from all you great minds, the info I learned just reading thru this is amazing and has made me dive into some deep chemistry rabbit holes, thank you all for sharing your info and findings. Grower love!
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The lab listed it as SO4, not elemental S. Multiply by .33 to get to elemental S.
@danielfp is far more qualified to comment on sodium bisulfate than I.
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Not specific to Athena, but the label for most cannabis-specific fertilizers (liquid or dry) can’t be trusted with verification. There’s a +/- variance allowed on the labeled nutrients, and many companies exceed the allowed variance due to incompetence or an attempt to retain their ‘secret sauce.’
There are many ways to list (and not list) items in an SDS and on a label that obfuscate the actual ingredients. And many companies don’t list everything even though they’re supposed to.
Where are you seeing sodium? It’s not listed on the labels, and @Medicine.grower’s lab didn’t test for Na. Considering it’s a micronutrient according to AAPFCO I would be surprised if Athena didn’t include Na if it was present in a non-trivial concentration.
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@Ralf
@Medicine.grower on their 55 gallon tested for sodium and Chorine.
I’m starting to think it’s just a small amount from biproduct from other salts. Still not sure however it makes me ask questions for such a “clean” nutrient.
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Thanks. I didn’t notice he tested for Na. I agree that is a small amount of sodium, which probally came from a few different salts.
Something I’ve noticed looking at my test results and the ones from @medicine.grower is that the copper is significantly higher than the label by 10x (.3 ppm instead of .03) and much more than most copper ppm in common hydroponic solutions and what is available in the Plant Prod chelated micros. I do see this on a Promix page talking about copper.
“Copper also serves to intensify flavor and color in vegetables and color in flowers.”
I ordered some copper EDTA from custom hydro.
Honestly though I’m probably just going to buy the Athena and use it. The Zinc is 2x what I can get with Plant Prod chelated micros also. If I’m going to have to single addition every micro to get to what Athena has exactly I’ll just buy the product rather than run more tests to see what the secret sauce is. As much as that kills me as a former scientist.
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I know that my terps have got much better then when I was using jacks, I also know I’ve been doing better growing so that also helps as well. But considering that my buddy is still using jacks and basically I controlled his garden for him last run, same genetics, medium, and dry method. Only difference is he’s using led and jacks. Vs cmh and athena.
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