Can I have it too humid in my humidity dome for germinating?

Indoor Growing
#1

Hi,
my humidity dome is now filled with over 230 starter cubes (rockwool) which I soaked with tap water before putting the seeds in them.

Temperature in the dome is set at 27 degree celsius or around 80 degree Fahrenheit.

Now I worry that my cubes are maybe too wet or that the humidity in the dome could be too high?

Is it possible that my seedlings rot and my cubes start to mold?

How often do I need to vent the dome? There are ventilation holes. At the moment I have them closed. Once per day I remove the lid of the dome for 5 minutes and let the air exchange.

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#2

I think you need to apply an extra helping of @ReikoX’s magic ingredient.

Course, some pics wouldn’'t hurt either, :wink:

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#3

As soon as they open and start pushing up you want to take the lid off and start reducing the humidity. btw did you check/adjust your tap water ph cos the starting point is around 5.5 in hydroponics?

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#4

algae might grow on the rockwool from the light, i don’t think it’s harmful tho… i dont think a humidity dome is necessary for seedlings unless your house was pretty arid. i’d have the vents fully open at least. i’m scared of damping off lol

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#5

Personally I’ve had very negative results using humidity domes even with the vent full open as my fan leaves tend to mold on me. I’ve had much better success with no lid in a semi lit area using a rooting mat with a thermostat .

Just my .02

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#6

Yeah I am worrying a bit about the ph now. I used the tap water instead of the osmosis water (no I regret that decision). I didn’t correct the ph as I didn’t think it wouldn’t be necessary for germinating, as I wouldn’t use fertilizer. But I guess that logic is not correct. I am going to the check the ph later again to see with what I am dealing.

I am going to remove the lids then.

And is it necessary to squeeze out the rockwool cubes or can I have them fully soaked?

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#7

I’ve not used rockwool for about 10 years now but i used to pre-soak the cubes in tap water & grow nutrient with a CF of about 0.6 and a PH of 5.5. I used to very gently squeeze the cubes to remove some excess water then i’d open up the wee hole a bit with a nail or something, drop the seed in no deeper than half a cm and put them in the propagator at about 25C. As soon as they split open take the top off but leave the heat on until they shed their seed hulls. Then under a bit brighter light and so on.

If you mix up water to the correct PH and spray the cubes you will most lightly be fine. If you do use reverse osmosis (RO) water you will need to add some cal-mag AND your nutrients when they get growing. A

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#8

So I need to add cal-mag to the fertilizer when using reverse osmosis water?

I checked my tap water. It has a ph of 7.1. I didn’t squeeze the rockwool cubes. So they are still pretty wet. Is there a need to handle the ph value of the cubes? Should I resoak them in ph adjusted water? Can the seedlings rot or drown in the rockwool cubes when they are too wet or is that not possible in rockwool?

#9

Yes you should use cal-mag with RO water.
Your seeds will still start with tap water at 7.1 however you should lower that as soon as poss with your very next watering to around 5.5.
And yes seedlings can rot in any medium including rockwool if it remains over saturated for too long. However rockwool cubes are easy to deal with, give them a gentle squeeze to remove some of the excess water.

Most importantly, don’t panic :thumbsup:

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#10

i remember reading somewhere grodan rockwool is no longer alkaline and are prebuffered to 5.8 or something… i think it was some youtube video and the guy actually contacted grodan and they confirmed that

you don’t need to pre-soak grodan rockwool, you can just water with your regular nutrient solution, but imho you have nothing to worry about buddy, just start PHing your solution going forward

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#11

Thanks guys!

I did read that I shouldn’t fertilize plants until the first set of true leaves shows up! Makes sense.

Should I add a small amount of hydrogen peroxide into the ph adjusted water for the seedlings? Or shouldn’t i do that now at all?

Also I want to hang my lights up now. I have four ebb and flow tables. Effective grow area is 1.1m 1.x1m each.The tables are in a rectangular room all in one line. walls begin 40cm from the table sides and are painted white.

I have four medium adjustAWings double ended light fixtures. I will put one fixture over each table.

But do I need to face the reflectors side by side or all in one line???

Here is a layout advice from the manufacturer itself.

https://www.adjustawings.com/produc…-hellion-lighting-system/hellion-layout-tips/

But still I don’t know if I should put them inline or side by side?

#12

I will put them in a line. Otherwise I might get too much light overlap.

Another question… The plants were stretching too much. So I lowered the lights. Now some of the plants leaves are curling down away from the lights. That means they get too much light? Unfortunately the plants which are placed at the ends of the lights are still stretching, what means they don’t get enough light… :-/

What a crap. My lights are 90cm only but the area which needs to be lighted is at least 100cm. Also it is around 50 cm wide…

What light/reflector fixture would you recommend me for an area of 100x50cm?

I will need it later also for propagating clones. So I will need to put the humidity dome on it. That means I will have the lights over the lid, and that means the lights will be in a height of around 30 cm.

Any recommendations, what I should get? LED would be too expensive?

Probably a 120cm t5 reflector fixture?

#13

I will install the hps lamps today and put the seedlings under them. My t5 lights are fucking the plants up, as the light coverage isn’t great and uniform enough. Some are stretching like shit. That needs to stop. Some stretch really strong and at the same time some get too much light. Unfortunately yesterday even 10 plants dried out yesterday.

For future i will get a 120cm 8 bulb t5 reflector set up. Now it is too late.

I have a question about the calmag products. In the calmag products there is normally contained nitrogen? I am planning to mix it myself.