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budmonger
03-15-2009, 08:19 PM
This is the recipe you need to follow written by Fet the former breeder for spice of life seeds....enjoy..

Using STS For Sex Reversal

There has been one key change that I want to pass along to everyone

I have discovered that using a stronger concentration of STS does not make a plant more likely to produce pollen. It just burns/stresses the plant. What DOES make a plant much more likely to complete it's mission and make pollen is a second spraying at the end of week 2.

My conclusion is that STS in any concentration is only effective at inhibiting ethylene for about 3 weeks; at that point the plant's natural female metabolism begins to take back control, and even a plant that is covered with male blooms can't finish the journey to manhood and produce pollen. A second spraying allows inhibition to last through week 6, which is more than enough time to release pollen.

Some of you have decided to use stronger concentrations of STS. This is fine as long as it doesn't burn your plants. Obviously there is a wide range of usable formulas that will work. But the second spraying is the key to follow-through. You can store the working solution you used for round one (in the spray bottle) in your refrigerator for two weeks; no need to mix a new batch from stock.

I don't see the point of going any stronger than the formula I originally came up with. It has proven itself many times over. The only change I might make is to adjust it slightly to Gobgoober's "molar-correct" mix ratio. This is not at all necessary, but does allow the most effective use of the chemicals together.

Here's a re-post of the formula mix instructions, with the adjusted recipe below that:

Preparation of STS:

First, a stock solution is made. It consists of two parts (A and B) that are initially mixed separately, then blended together. Part A is ALWAYS mixed into part B while stirring rapidly. Use distilled water; tap water may cause precipitates to form.

Wear gloves while mixing and using these chemicals, and mix and use in a properly ventilated area. A mask will prevent the breathing of any dust, which is caustic. STS is colorless and odorless, and poses minimal health risks if used as described here. (See material safety data sheet links below). Note that silver nitrate and STS can cause brown stains upon drying, so spray over newspaper and avoid spilling.

Part A: .5 gram silver nitrate stirred into 500ml distilled water
Part B: 2.5 grams sodium thiosulfate (anhydrous) stirred into 500ml distilled water

The silver nitrate dissolves within 15 seconds. The sodium thiosulfate takes 30-45 seconds to dissolve.

The silver nitrate solution (A) is then mixed into the sodium thiosulfate solution (B) while stirring rapidly. The resulting blend is stock silver thiosulfate solution (STS).

This stock solution is then diluted at a ratio of 1:9 to make a working solution. For example, 100ml of stock STS is added to 900ml of distilled water. This is then sprayed on select female plants.

Both the stock STS and the working solution should be refrigerated after use, as well as the powdered chemicals, to avoid activity loss.

The adjusted formula is as follows:

Part A: .7 gram silver nitrate stirred into 40ml distilled water
Part B: 2.6 grams sodium thiosulfate (anhydrous) stirred into 160 ml distilled water

Next, slowly add the silver nitrate solution to the sodium thiosulfate solution while stirring. This combination is then added to 800 ml of distilled water to equal 1 liter. This is your final stock solution. It is diluted 1:9 with more distilled water to make your final working solution, which then gets sprayed on your target plant.

Either formula will work great, so don't sweat it too much. But do that second spraying at the end of week 2... seems to be the key for getting pollen from the more difficult strains.



hey all i guess with that recipe it didnt work to well this one is from Reeferman thanks Reeferman!!

PREPARATION OF SILVER THIOSULFATE (STS) SOLUTION

Silver Thiosulfate (STS) is commonly used to block the action of ethylene in plant cell cultures.
Ethylene is a hormone that is present in the gaseous state. Ethylene increases during
senescence and ripening, and has been shown to increase in plant cell cultures due to
wounding or the presence of auxins. Silver nitrate may be used alone to block the action of
ethylene but it is not transported as well as STS thus is seldom used alone.

Prepare a 0.1 M Sodium Thiosulfate (STS) stock solution by dissolving 1.58 g of Sodium
Thiosulfate (Product No. S 620) into 100 ml of water. Prepare a 0.1 M Silver Nitrate stock
solution by dissolving 1.7 g of Silver Nitrate (Product No. S 169) into 100 ml of water. Store the
stock solution in the dark until needed to prepare the STS.

The STS solution is prepared with a molar ratio between silver and thiosulfate of 1:4,
respectively. Nearly all of the silver present in the solution is in the form of [Ag (S2O3)2]3-, the
active complex for ethylene effect inhibition.

Prepare a 0.02 M STS by slowly pouring 20 ml of 0.1 M silver nitrate stock solution into 80 ml of
0.1 M sodium thiosulfate stock solution. The STS can be stored in the refrigerator for up to a
month. However, preparation of the STS just prior to use is recommended.

be well.Peace and stay safe...budmonger