Plants have me stumped

G’day guys,
I’ve had 2 grows in total indoors, (plenty outside)and learning things along the way like too much light = not good, buy aircon etc. Anyway I became cocky, but also tried using a pot I’d make from a 20 litre"handy Pale" which is 30cm wide, & 40cm deep. This gave me more room for more meds. The older growing buckets were 50cm wide x 30cm deep. From harvesting I noticed the roots would not go the near the 50cm wide pots but would tangle up down the bottom (they were 52litre pots). So I figured to give them that extra 10cm depth that the roots appreciated with the 20litre pots. It’s all been good, but the the last week of veg I noticed some Fungal Gnats & watered them 2litres each in the 20litre pots "cost me about $150 for 400ml bottles of 6% hydrogen peroxide which I mixed up 8 to 1 ratio that I had used before on a separate infestation. All my soil mixes are organic & drain almost instantly out of the different pots I have used. I was using a combination of Sea Sol seaweed ferts, As well as CANNA BIO TERRA VEGA during veg. But last watering was about 10days ago using hydrogen peroxide for any Gnat larvae in the soil. My water gauge shows soil is still medium from above, and from a drainage hole from the bottom is totally soaking wet that dosnt make sense as I gave 2litres of water slowly, and extracted almost 1.5litres out of the over fill dish at the bottom. The fan leaves are all going yellow, the wet tells me don’t water, and I haven’t given nutes for 3 to 4 weeks “I have it written down”. I am going to try sending a few fotos so you get the gist, and is there anyone who can give a sensible diagnosis would make me very happy, as I’m clueless of what’s going on? I have broken 12 ribs in a bike accident last week, but if I have to I’ll change back to the bigger pots with new soil so be it. The big pots take up so much space and Gnat Nix which I believe I have the last 3 bags in the world and really don’t want to be frivolous with it. The pots sit on wheels about 5cm high so they have plenty of air to dry out, but putting my finger in the holes the soil medium is still wet? Do I get my air compressor out and stick it in the holes to blast out excess water? And if if it is excess water is this what is making all the fan leaves go yellow? Or do I need to add some N to boost the green? Thanks for any educated replies are very much appreciated

. The grow is Critical Mass, Power Plant, & Girl Scout Cookies Extreme.


In all that information you just gave I didn’t see one of the most important things needed to know. What’s the ph going in and coming out?


So you actually watered the soil with a hydrogen peroxide solution? I’ve never heard of that. I know it reacts when it hits organic soil. I think you have a chemical reaction going on that is burning your plants root system.

Let’s tag @Myfriendis410

1 Like

I have heard of peroxide in the top of the soil layer as a way to kill fungus gnats/maggots. You are right in that it will break down very quickly but if used in soil you will need to re apply mykos as it will kill it.

1 Like

Cool, PH in all my soil indoor grows have been 6 to 6.8.

From what I gather as well as what my last 2 grows were, these are good soil Pc’s. Correct me if I’m wrong, but I got it from a reputable source (I think it came from Roberts grow bible)? As for going out, that has never occurred to me so Thankyou I will test the drainage water next watering.

From what I understand h2o2 poured directly into your soil will kill your microbes as well as mess with your roots.
Gnat nix supposedly works, but it didn’t do crap for me.
BTi, whether in mosquito bits or powder form (available on eBay), is the best solution I’ve discovered for fungus gnats.

Your plants are hungry for nitrogen. Since the microbe population is now dead you’ll need to bring it back as well as supplement some nitrogen ASAP.

Runoff numbers will tell us more

Wow. It’s $.80 US for a liter of 3% here.

Thankyou to the rest of you. I will get my compressor out with a long nozzle, and use that in the soil to drive any moisture out (obviously on a low PSI). So if the roots have burnt, should I just be using plain de chlorinated water? Or should I add a little SEASOL to the mix?

I was in a lot of pain last night from the accident, but managed to poke 8-10 12mm holes from top all the way to the bottom, and I’m not sure if it looks better, like a placebo affect? But the tops of the plants have perked up(not sure if I made that word up). Thankyou, am keen on some more information unless it has been said and is a big full stop from there. Am just waiting for what others would do in this situation as they have just started to show flowers and would like to nip this in the bud quickly if I can. Hope everyone’s grow is doing dynamite!

Good move on adding the additional holes in the buckets.
Hydrogen Peroxide will as they said above kill many things that you don’t want to kill and some that you do like the gnat larvae but the best thing I’ve found to deal with them is using BTi as posted above. You spread them onto the top soil before you water and them when watering the BTi critters that eat the gnat larvae will be released into the soil where the gnat larvae are.

I would just let them dry out by themselves rather than using a compressor to do that. Overwatering can cause the fungus to grow on the top of the soil (green stuff) and that’s what attracts fungus gnats.

Hope this helps

Thanks mate, Everyone who has answered has imparted that bit more knowledge on my techniques! Growing indoors I send a kudos to all as I find it so relaxing sitting in the flower or grow room, yet some tiny unwanted little buggas can turn that relaxation mode into an all out freak attack when it happens. Still has me stumped where their coming from? My best guess is the soil & compost mixes. Cheers and good wishes to all!

Yeah, I bought about 14 x 6% bottles that contain 400ml in each depending on the chemist a 400ml bottle was $10-$15. I don’t want to repeat that again. Will do on the bringing soil nutes & run off tomorrow using only a mild SEASOL, and I will post for help if things are looking off. I’ve still got 1 & 1/2 Plants of Super Lemon Haze to trim up tomorrow as I put them in pitch black in a spare bathroom, with only the suction running. I was supposed to only keep them in pitch black for max 72hrs, but being T boned by an old lady kept me in hospital
and them in the dark for 8days. On arrival Trichomes were so full, buds had turned purple on the SLH’s, but the White Widow didn’t look all that great. I used hang with all leaves on as my ribs didn’t let me do anything else. Using this method I have got the stinkiest, perfectly dried, easiest trimming weed I’ve ever had. I was a wet trimmer, but never again. Thanks for your help mate!

I have finally watered them, I may have to repot? They drain perfectly but tend to hold that last 2 inches in the bottom totally soaked. I have bought a 500mm x 15mm long auger bit and have drilled another 10 more holes in each one, still staying wet? (has me totally stuffed?) I bought a dozen of those big fishtank airators, and have left 1each in pot bottom hole, running to see what that will do? Too early to say bar they look like they have pepped up abit. I’m starting to think the 5 types of Organic manure (its called 5in1) I reckon the manure may be too fresh as it squeezes like clay when i was starting my next seedlings into larger pots? Watered today with a teeny bit of Sea Sol & Drinkslinger I checked the run off water as you suggested and it comes back 6.8-6.9. Is this an ok figure? Soil always comes back when tested at 5.9-6.1 All flowers are coming up nice and green and healthy looking, it is just the 8/10’s downwards that the plants are staying yellow?