A few new plants have yellow and browning tips

I’m getting these brown and yellow leaf tips again. Last time I thought it was from a fungus potentially from dust so I bought a new carbon filter and ducting and cleaned every inch of the tent thoroughly.

The carbon filter cover is already covered in a thick white dust and the exhaust fan is barely blowing any air out.

I vacuumed the cover and now the airflow is normal.

Why is the cover getting so dusty? The only thing I can think of I got a new humidifier and it’s pretty humid (65%). Or maybe the room is dusty? There is a slightly opened window right next to the tent and I just have the ducting next to that. But at night it gets too cold and I have to close the window. Is it the air in my grow room that is dusty?

Anyway should I clip off the tips that are brown or just leave it?

I’m using 5 gallon air pots, strains are gelato and Girl Scout cookies autoflower, I’m downing a 24 hour light cycle and using organic dry amendments.


The cause of this is using tap water in an ultrasonic humidifier. Ultrasonic humidifiers aerosolize the minerals in tap water. Get a wicking humidifier or use distilled or RO water in it.


Other than the tips being a little Brown plants look healthy. You can wash the prefilter if you like an let it dry put it back on. :v::+1:


Looks like u have drop water on ur leaves to me


Noticing a water ring around the base of the main I would assume you spilled some water/nutrients on those leaves. The others have you covered on the filter residue :love_you_gesture:


You really don’t have to use a carbon filter until flower you will extend the life of the filter


I didn’t know that I thought it should always be used. Thanks.

So the dust is the minerals evaporated form the water? I have a Brita filter I use for drinking water. I’m using it to water the plants and if I also use it for the humidifier I should be good?

Okay good glad it’s not that serious

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I think I did drop some water but didn’t know it would make it turn brown?

All of the new growth looks great you won’t recognize the plant in a couple of weeks. Keep up the good work :+1::v:


A brita filter will not remove dissolved minerals.


I think I did the same thing, spraying seedlings and maybe lights too hot. Adjusted to pouring water and adjusted lights – no more yellow tips.

I use a Zero water filter – it’s fast and does a better job than my Brita did.

It happens to all of us bro dont worry about it

Calcium and mineral deposits from tap go all around the house. I have a son with asthma, and constant use of a humidifier using tap water, everything gets covered with water vapor (humidity). You only see it when it dries up.

The reading glasses I leave in my grow room get covered with calcium dust. The cost of distilled water would be prohibitive at this time - and spring is coming, with it’s attendant humidity. Yesterday we had a freak day at 79F with thunderstorms, and the humidifiers hardly ran.

And this is with my main tent venting outside. I always figure calcium is calcium, right? :wink: