Boil K-lite stock to avoid mold growth?

[tropterrarium]

I currently have a lot of problems with plants rotting at base. Temps are >60 so don't think it is that. Have increased airflow, but jury still out.

The rotting problem coincides with switching to K-lite. I dissolve the 1 lb powder in 5 gals RO water in a 5 gal bucket. On top, there is a solid layer of mold growing. Have been thinking that the mold may produce toxins that kill the plants. Or that when I spray the plants with mold-containing water&fertilizer, I spray them with a nice inoculate of mold.

So how to sterilize the K-lite stock? Thought about boiling the RO water first for half an hour, then add K-lite powder, boil a bit more, then fill into sterilized glass bottles.

Is there a problem with boiling stock fertilizer? Higher temperature should increase solubility of minerals, just wonder whether there are negative issues.

[Ray]

The problem is probably bacteria, not mold, and it originates with the environment, not within the water or fertilizer, so while boiling it isn't going to hurt the fertilizer too much, it isn't going to stop the issue, either. (FWIW, I see that on all fertilizer concentrates that are open to the air, but I see no increase in rots when it does.) Bacteria just LOVE nitrogen!

Some folks put a germicidal UV lamp over their stock tanks, while others add disinfectants. Have you considered adding some Physan to the tank?

[ALToronto]

I pour boiling water over K-Lite crystals to dissolve them, then keep the concentrate in the fridge. I only mix 1 litre of concentrate at a time. No mold at all for several months.

Any other combination results in mold. No boiling water + fridge = mold. Boiling water + no fridge = mold. Obviously, if you don't boil the water and don't keep the concentrate in the fridge, you will get a lot more mold, much faster.

[Joseia]

Dumb question time: is there a reason for pre-mixing the klite in such large batches and then letting it sit around? Or is it nothing more than you folks have ALOT more orchids than me and do everything in large batches to save time? Just curious.

[jeremyinsf]

I make three to five gallons of pre-mix at once. And I don't use it all in one day, or even all in one week. I asked Ray about this some time ago, and took the Physan suggestion. It only takes a very small amount to control the growth, and I don't have to boil or refrigerate it. My KelpMax takes up too much room in the fridge already :-)

And yes, I probably do have that many more orchids!

[ALToronto]

Originally Posted by Joseia

Dumb question time: is there a reason for pre-mixing the klite in such large batches and then letting it sit around? Or is it nothing more than you folks have ALOT more orchids than me and do everything in large batches to save time? Just curious.

I don't dissolve such large amounts. But you do need to make a strong concentrate because the mixture of ingredients is very heterogeneous, and you need to make sure that you have a complete blend.

I dissolve 33 g of crystals in 1 litre of water to get 4000 ppm N. Then 30 ml of concentrate in 4 litres of water gives me 30 ppm N. That's one day's water for all my plants, orchids and a few ordinary houseplants.

[zxyqu]

Yes the reason for making a premix is as suggested by others. Really some of us have more orchids but the best reason is to normalize the overall mixture to a measurable use. One scoop of a this and that mix might give you variable NPK ratio than the next scoop. Really you probably don't need to, but it's a personal choice. As to the growths, definitely consider the Physan addition. Works well.

[Bud]

I dissolve K-lite crystals in tepid water from the sink to help dissolve it and add to a gallon of water.
But I make sure to use up all the batch I mixed for that day. I don't save mixed fertilizer in a container= that will invite bacteria to grow.

[terryros]

I will vote with the refrigeration. I make up 500 mL of stock solution at a time and keep the stock refrigerated always. I got K-Lite when it first came out and didn't refrigerate for the first month or so and did get particulates developing. In the last year or two I never have anything but clear solution when I measure out the stock for dilution into the feeding solution.


Sent from my iPad using Tapatalk HD

[bethmarie]

I went with AlToronto's recipe + physan and it's working out great. I also tend to keep it in the fridge.

Thanks for this thread. I found it helpful.