First time growing CVG (Natalensis)

I'm looking for help, I believe I may have contamination or too much mosture / lack of fresh air.

Sent to fruiting on October 1st. Humidity 95-99% Temperature 22c Exhaust fan runs every 4 hours for 15min.

Any help or insight is greatly appreciated 🙏

Hey Chris!

1. Your cakes don't look contaminated. There is some yellowish looking mycelium, but it's kind of pigmentation or metabolites.

2. There is no water drops on the mycelium, which means everything is fine with humidity. Although I prefer to keep RH about 90% in a grow tent. Do you use humidifier?

3. Natals are a heat-tolerant species, so 22°C is great and real chilling for them.

4. Hard to say about CO2 level in tent, but on eye for such tent and relatively average-size cakes FAE every 4 hours for 15 mins should be enough.

Do you aware about agressive Natals' mycelium growth?

Do you know that they are tend to overlay?

Did you use casing layer based on peat moss?

I hope this example will shed some light on growing Natals ;) https://shroomok.com/en/wiki/Natalensis_grow_bag_fruiting_and_overlay_problems

I used more cococoir as a casing layer. I did press it all down, maybe a mistake.

yes I have a humidifier (AC Infinity)

I'm frustrated and concerned because I followed the CVG guide online to the T and my cococoir had way too much water. I squeezed out 10 cups of extra water before I reached Field capacity.

I hope you're correct in the thought that it's just metabolites. I guess time will tell.

I've also increased my exhaust fan a little more. thinking it might have been too low.

thank you very much for your response and insight.

I'll keep you updated.

You're welcome!

"I did press it all down, maybe a mistake."

No, it's not a mistake :)

"I've also increased my exhaust fan a little more. thinking it might have been too low."

Better to run it more frequently or a lil bit longer, but I'd use up to 30% of airflow power, since hard airflow may dry out the top layer and exhaust fan suck in more dirty air (it's another topic on how to make proper ventilation for tent). I'd also run a humidifier (20-30% of its power) while ventilating the tent.

Tell me please what is your tent size L x W x H? So that I can calculate its volume.

What type (or model) of fan do you have? What diameter? And if you know, what is the airflow capacity? So that I can calculate required air exchange and frequency for your tent.

You have 4 cakes right now. Would you mind choosing 1-2 of them for the experiment? Don't worry, I'll guide you! Let's make them fruit and compare results with the rest cakes ;)

My fan is a Hon&Guan 4 Inch Inline Booster Duct Fan with Speed Controller - 130 CFM.

While the tent is venting my AC Infinity humidifier turns on automatically as it's set to a fixed relative humidity. 90%

Yes I'm more than happy to experiment ☺️

I cannot express how grateful I am for your assistance 🙏

Great! Let's have fun :-)

I'll get back to you with calculations and step-by-step instructions soon

Fan Speed and Runtime calculations based on grow tent volume and fan output

TL;DR

For your martha tent volume 22.2 ft³ you need to run the fan at 15-10% speed for only 5-9 minutes accordingly to make 4-5 air changes. Once in every 4 hrs is fine since your tent is not fully loaded, there are only 4 cakes, I'd say it's 1/4 of its capacity.

Btw, do you use a timer or smart plug, or anything else for fan?

If you are interested in calculations, here they are. Maybe someone else will also find them useful and use as an example:

Grow tent volume

Your tent size is: 19'' × 27" × 75" (inches)

Convert inches to ft: 1 inch = 0.0833..

Tent Volume = 1.58 ft x 2.25 ft x 6.25 ft = 22.2 (ft³)

Required airflow for tent

Note: Here I calculate airflow per minute to match and compare with fan CFM (cubic feet per minute) output.

Let’s make about 4–5 full air changes (per hour), this will be enough to remove CO2 (diluted with fresh air as well).

Required airflow (CFM) per minute = (Volume × Exchanges per hour) / 60 mins

22.2 ft³ * 4 air changes/ hour = 88.8 ft/hour = 88.8 / 60 = 1.48 CFM (per minute)

22.2 ft³ * 5 air changes/hour = 111 ft/hour = 111 / 60 = 1.85 CFM (per minute)

So, you need approx. between 1.5–1.9 CFM to meet your air exchange goal

Fan output

Your fan output = 130 CFM (cubic feet per minute) at 100% speed

But for your tent volume you only need 1.5-1.9 CFM

At 15% speed:

130 x 0.15 = 19.5 CFM — it’s still 10x times more than you need

So if you turn on your fan at 15% speed for 5-6 mins this will be:

19.5 CFU / 60mins * 5(6) mins = 1.6-1.95 CFM, which is within your goal

At 10% speed:

130 x 0.10 = 13 CFM

So if you turn on your fan at 10% speed for 7-9 mins this will be:

13 CFU / 60 mins * 7(9) mins = 1.5 - 1.95 CFM, which is within your goal

As you can see, you don’t need to run the fan at full 100% speed and 15 mins is too much at any speed!

That's it :)