Femanizing pollen and seeds. And an STS how to!

Ok growers network. In this thread we’re going to make silver thiosulfate solution. For the purpose of producing femanized pollen. But im going to go a tiny bit further and produce femanized seeds at the same time im producing the femanized pollen. I have 2 strains ill be doing to test out the effectiveness of the sts solution i made. 1. Runtz 2. Slapz.
So lets get started.
Ok i put news paper over the tops of the soil. Turned off lights and fan. Then sprayed both girls. With the help of a green led work light.
Now ill go down and put the lights back-to-auto timer and take the newspapers off rootzones. And in 5 days WE FLIP!


1x digital scale. To weigh powder crystals.
1x 16 oz brown glass spray bottle.
2x 500ml brown glass bottles.
2 x 500ml beakers/pyrex 2cup or one if you want to wash in between making part A and B.
1x manetic mixer plate or metal whisk.
2x 60ml/cc syringes no needle.
Metal spoons for scooping powder into boats.
Small measuring/weighing boats.

  1. Silvernitrate
  2. Sodium thiosulfate
  3. R/O Water.
    Safety glasses.
    Painters mask.
    Pair of Rubber gloves.

    Here is the stuff needed laid out. I dont have the syringes until tomorrow. And ill show how to mix part A&B.

So lets get mixing - safety 1st. Gear up. Gloves,mask,safety glasses.

Take a 500ml beaker and set it on the magnetic stirring plate put in a stirring bar.
Take a bottle of water. Its exactly 500ml. Dump it into the beaker on the stirring plate. And turn the magnetic
stirrer up to 75% Get it stirring.

Next get your scale out. Put a boat measuring tray on the scale and measure out. .5 grams of of silver nitrate. Using a spoon be CAREFUL.

Now SLOWLY pour the silver nitrate into the R/O water mix in while whisking until disolved. About 20seconds.

After mixing this first solution part “A” take it and pour it into a 500 ml glass jar well marked. Solution A

Ok part A done half way there.
Next take another beaker and set in on the stirring plate stirring bar and add 500ml of R/O water.
Get the plate stirring. Like before.

Get you scale and measuring boat/tray. On scale and measure out 2.5g of sodium thiosulfate.

Now SLOWLY pour the powdered crystals into the R/0 water on the stirring plate until dissolved about 45 seconds.

After mixing is finished pour the solution into the second 500ml bottle labeled STS part “B”

Ok take both bottles of part A&B and put them in the fridge.

Here are the ladies. Tomorrow ill spray the plants after i show you how to make the final solution mixture out of parts A&B by mixing them.

Ok the journey continues tomorrow.

Mixing and Diluting the Stock Solutions Before Spraying

ALWAYS Mix Part A in to Part B! This means putting part B in a container first and then adding part A while stirring. The measurements listed here make 1 quart, which fits the size of the sprayer and bottles I posted above. This amount provides plenty of solution for a 2’ tall plant, sprayed every 5 days for 30 days.

When stored in a dark cool place, the mixed solution is effective for approximately 1 month. The A and B solutions will be effective for at least 6 months.

For 1 Quart of Solution: which will fit the sprayer listed:

  • Use a 60cc syringe and suck up 50ml of Part B solution
  • Gently squirt the Part B solution in to the Pyrex measuring cup
  • Completely rinse the syringe or use a second clean syringe.
  • Suck up 50cc of Part A Solution
  • While stirring the stock solution in the measuring cup rapidly

    use a magnetic stirring plate Or [Stainless Steel Whisk] gently squirt the 50cc’s of Part A solution in to the measuring cup. Go slowly, yet quickly enough to completely mix them within 30 seconds.
    Ok Done mixing.


Without dilution this solution will burn plants When the above directions are followed you will have 100ml of mixed stock solution in a pyrex measuring cup. Pour this solution into the 1 quart, brown glass bottle with the sprayer top and then fill the bottle the rest of the way with r/o or distilled water. (800+ml)

This dilution rate is very close to a 1:9, stock:water mixture. Add 6-10 drops of Dawn Ultra dish soap (or other soap/surfactant, some people use yucca extract), shake gently and spray until the soap mixture is being sprayed. Test it on a leaf. The mixture should stick to the leaf without beading up and rolling off.

If necessary, add additional drops of soap until the solution sticks/spreads well. You can also use Yucca extract as a spreader/surfactant, instead of the dish soap. I did not use dish soap. Im trying without it.

Light Proof the Sprayer Bottle!

I know it’s a brown glass bottle and a black plastic top, I still covered it further. Since I keep it in the fridge, there is definitely strong light when the door is open. :wink: I wrapped the sprayer bottle in black electric tape You can see it in the photo.

Staying Safe!

WEAR PERSONAL PROTECTION GEAR, including gloves, mask and goggles/glasses. You’ll want to keep this off your skin and out of your mouth/lungs. Sodium Thiosulfate has no listed toxicity but it is an irritant with repeated exposure. Silver nitrate will stain surfaces brown, only light stains when mixed with sodium thiosulfate and diluted.

This was not me! A word of caution.

“I sprayed my hand once, it felt ‘cold’ for days. Not a good sign, so I’m careful to protect myself from spray and inhalation. The solution rinses off of gloves and surfaces just fine, change out of any clothing you accidentally spill it on.”

Spraying Methods and Schedule

That being said, the process of treating your plants with STS is very straightforward. There’s debate about spraying each node or using an eye-dropper on each node. I use the spray method and I know it works.

  • Spray Every 5 Days After Lights Out
    Silver Thiosulfate stops the production of ethylene. This effect only lasts a few days in cannabis and spraying every 5 days keeps ethylene production the lowest. Turn off the main lights and spray before the night cycle. Silver thiosulfate is sensitive to light, so low lighting and then dark works well.
  • Dilute Further if Burning/Yellowing Develops
    Some strains/phenotypes of cannabis are more sensitive than others. Should yellowing or burning develop, pour out some of the solution in the sprayer (with lots of rinse water down the drain) and add distilled or r/o water.
  • Keep STS Out of the Root Zone
    Cover the base area of the plant with newspapers before spraying. Make sure the plant has completely stopped dripping before removing the newspapers or other barriers.
  • Saturate Each Node With Spray
    The nodes are located at each spot where a leaf joins a branch. During vegetative growth, each node will eventually produce another branch. During flowering, each node produces flowers.

Dilute Solution if Plants Show Burning
A slight reaction is fine, while severe reactions require diluting with additional distilled or r/o water. Open up the spray bottle and top it off with about 1/3rd of a cup of distilled or r/o water. Pour a bit out first, if there won’t be room.

https://phytotechlab.com/ supplies

Instructions im using.

I hope it works out well.

@MrBlue @scotty17 @Hydro @mayakid @bobette @Olcoot @happyhippy @thedreamer @jaxsonl5 @LasVegas7 @OltimeGrower @Jimhigh66 @katmwall i know i missed a lot of people.


tks Prey cant wait til tomorrow to learn how to complete the process


Very interesting!
Following along.
Quite a process.
Thanks Preybird. :green_heart:


Hmm I’ve heard of colloidal silver before but not this. Interested.


Diggin the PPE and mag stir plate, hell yeah! Great step-by-step instructions, thanks @PreyBird1.


Prey, you are the pollen man!
This looks very interesting.
With your mask on it looks like some Breaking Bad/Walter White business going down.:flushed:
Thanks for the tag.:fist:


Very interesting :face_with_monocle: thread @PreyBird1 thanks for the info!


Good luck @PreyBird1 . Wish I could afford all that fancy stuff like a magnetic stirrer. My wife’s arm gets tired too easy.


This is super cool prey. I’ll be watching.





Lol your wifes arm ha ha ha. I have this equipment for my tissue culture lab. It definatly made it super quick and easy. @mayakid


So glad u started this thread bro


Very interesting I need to see this!


What is the purity of the two silver nitrate and Sodium thiosulfate? I know on a lot of chemicals, they come in varying purities.

Thanks and watching!


Ill check. I buy from this place because there mission is to have thee best quality raw ingrdients.

Looks like 99% and 97%

Once i get my propagation muskagi agar recipe the way i want it ill have them make my jars pre-filled with my recipe.


When I look up silver nitrate it says cant be shipped to residential addresses


@sssportsmfg - a key thing to look out for is “anhydrous” vs hydrates of a compound…it changes the molecules “weight” (hydrated versions just have water molecules “bound” in) and hence how much you need to add. The anhydrous form of a compound is more expensive and is “true” to its structure. If that made any sense :crazy_face:

@Hydro - because it’s an oxidizer and corrosive compound. If you’re in the US this place sells it to residential (it’s in small amounts and for home-school purposes so they can bypass those shipping regulations):


The amounts they sell are perfect actually for single batches of STS prep.


Professor P :facepunch:t2:


Lol send it to your work.


Yes @jaxsonl5 thats good to know.
I didn’t know that. Thanks.

The sodium nitrate says acs reagent. Dont see anhydrus on it. That stuff freaks me out…im leaving it in a pitch black cubboard.