2-week-old seedling trouble. What's wrong?

[Socrates]

Hi all,

I've got a few babies that are about 2 weeks from seed. They're being grown under LEDs in a mix of Fox Farm Ocean Forest and Happy Frog, with a little perlite and vermiculite. Temps are around 80-82 during the day and 70 at night. They were being watered with tap water (I don't know the PH, don't have a way to test right now), but I switched today to distilled bottled water in case that might be the problem. I also gave them one half-strength feeding of BioThrive Grow a few days ago, thinking that it might be an N deficiency. Let me know if any other info could help with the diagnosis.

I was thinking either that the soil is somehow too hot for them, resulting in nute burn, or that there's not enough N. Not really sure how to proceed. I just want them to be healthy!

 

[Neo 420]

You need to know your ph of your h20. FF by itself will not provide any buffer of PH. Since you changed the water has there been improvement/worsening?

 

[Socrates]

No improvement since changing the water, but I only did so this morning. I got the only PH test kits that were available nearby, though I fear they are quite shitty. Here are the results. The vial on the left is just the plain tap water, and the vial on the right is the tap water mixed with the soil (as the test is meant to be used). It looks to me as though the water is somewhat alkaline, but that mixed with the soil, it is coming out about right (6.5 - 6.8 ish?). Not really sure what to make of this. Thoughts?

 

[Neo 420]

Tests look good. If the problem is not worsening since changing the water, that may be a good sign. The damaged pieces are not going to repair, so look at all other growth. I wouldn't feed anything yet. Can I see a full viiew of the lady?

 

[Socrates]

Sure thing, here's one of that lady, and of the whole cab (more than half are having similar issues). So, if it's not a pH issue, what is most likely? Maybe soil too hot for seedlings? Slight nitrogen deficiency? Outgassing from the reflective lining? Aliens?

 

[PoopyTeaBags]

its not nitrogen it looks like its alittle to hot or mag issue from not enough mag or little high ph... thats what i get out of it... without a electronic tester its hard to pinpoint.

 

[PoopyTeaBags]

if you add dolomite lime to your soil you will not need to ph and itll auto ph to around 7.0 for ya so you can remove a variable... and its also a source of cal/mag if im not mistaken.

 

[Socrates]

Alright, thanks. I'll throw a little epsom salt in the next watering to see if it helps. Can I just add a bit of the lime to the top of the soil, or do I need to repot?

 

[PoopyTeaBags]

if its crushed should be ok to top soil but this is not my area of expertise... however if you repot just mix it in.. someone on here knows the rates to mix it i dont however...

 

[BongToke]

Alright, thanks. I'll throw a little epsom salt in the next watering to see if it helps. Can I just add a bit of the lime to the top of the soil, or do I need to repot?

ye top dressing with dolomite lime is cool, just dig up the surface of the dirt a lil when adding the dolomite then water er in

 

[Tonatiuh]

ffof is probably too hot for the seedlings,also u may be over watering a little bit.its easy to love them just a little too much sometimes.for sure need a ph pen,but all in all i think they dont look bad for having been started in some strong soil.i start seeds in light warrior for that reason.
look at the new growth,if its not affected problem is probably under control.
peace-T-

 

[Neo 420]

look at the new growth,if its not affected problem is probably under control.
peace-T-

Yeps......

 

[SeaMaiden]

Based on those pH tests you depict, I would not add anything that will further drive pH up (like dolomite lime). MgSO4 (Epsom salts) can be given as a foliar application as well as root fed, and I'm thinking slight Mg-. However, before you go and do that, I would get the the soil pH down just a bit, and would use water with a much lower pH. You see how dark your water-only sample is? It's over 8.0, and that's going to accumulate over time in your media, thus driving pH up even more. Dolomitic lime is used in aquaria (saltwater and African rift lake cichlids) in order to keep the water column at a pH of 8+, some of these fish need a pH of 9, and again, DL is what's often used. That, or crushed coral.

I would use filtered water, or filter my source water through peat or something that will soften it and lower the pH. I would give a foliar feeding of MgSO4 at the rate of 1/4tsp/gal (use a surfactant as well, a drop or two of liquid dish soap is fine, but make sure it's not an antimicrobial soap).

 

[Santa1949]

I'm with SeaMaiden here----ph way tooooo high.....2 wks old? Good growth!!!!! Looks like a small box, temps probably are affecting it(need cooler intake air).......try your ph down to 5.7 - 6, no higher....
1/4 nutes this age is still heavy......

Good luck.......

 

[nameless]

Based on those pH tests you depict, I would not add anything that will further drive pH up (like dolomite lime). MgSO4 (Epsom salts) can be given as a foliar application as well as root fed, and I'm thinking slight Mg-. However, before you go and do that, I would get the the soil pH down just a bit, and would use water with a much lower pH. You see how dark your water-only sample is? It's over 8.0, and that's going to accumulate over time in your media, thus driving pH up even more. Dolomitic lime is used in aquaria (saltwater and African rift lake cichlids) in order to keep the water column at a pH of 8+, some of these fish need a pH of 9, and again, DL is what's often used. That, or crushed coral.

I would use filtered water, or filter my source water through peat or something that will soften it and lower the pH. I would give a foliar feeding of MgSO4 at the rate of 1/4tsp/gal (use a surfactant as well, a drop or two of liquid dish soap is fine, but make sure it's not an antimicrobial soap).

hey girl! i know you know your stuff so i want to ask you, how does lime raise the ph of the soil? i thought it just made it stick to 7ish. i mix my own organic peat based soils and have been doing so for awhile now so i feel like i should know this... my plants are always fine, on occasion i have bits of trouble after transplanting if the soil hasnt cooked enough for the ph to stabilize, but it always levels out after a week or so of having a plant in it.

my suggestion to the op was going to be ph or cal/mag issues. both of which could be fixed (in my world) with a fresh batch of soil with some lime mixed in. i am unfamiliar with top dressing with lime. if it was me id leave them alone because, like my plants do, they seemed to have regulated themselves. for further mixes maybe ligten up on the ffof for the little ones as nearly everything gets burned by it as a seedling. personally i pop beans and clones into a three way mix of plain peat, ffof, and worm castings. split 50% - 50% - 50%

PM me if you dont mind sea maiden, TIA

 

[SeaMaiden]

Dolomite lime is chemically expressed as CaMgCO3. That's calcium magnesium carbonate. It's the CO3 part (carbonate) of the molecule that creates alkalinity (resistance to pH shift) as well as usually trending towards a basic pH. IME with water it tends to land pretty hard in the 8 range, but that's without the addition of a softener/acidifier such as peat moss, which would naturally counteract/counterbalance the carbonates present in the DL. Peat is what I recommend to acidify and soften water for delicate fishes, it works very well for that.

I'm not the best person to ask what's happening specifically on a molecular basis here, there are others who can explain far better and more eloquently than I.

I have never been able to bring myself to pay for the Fox Farms soils, so I've never used it and so have never spoken to it. I like Gardener & Bloom soils, again being cheap I get the cheaper potting soils and don't worry about a seedling mix. I reuse as much as I possibly can.

I see nothing that indicates a Ca issue, though that one dried up leaf tip is something I've seen but not been able to definitively diagnose in a young seedling, but RH could be an issue. Once I began using Ca and Mg separately (indoor coco coir cultivation and perlite hempy tubs) it immediately became very easy to distinguish a Ca- from a Mg-, and they're quite different. They're offered together in mixes because there's a ratio for them to play well and people like Mg because it often helps plants green back up very quickly.

 

[joe guy]

Just started fuckin with beans but i soak them when they sink i toos them in a ready grow plug.. Add lil rootbastic and watch the show.. That way hav some what a root structure b4 putting them in ffof
I was doin a 50/50 ffof canna cocco but can nolonger afford the.cocco so i just try and strengthen the seedling up b4 puting it in and the ffof has enough stuff to feed the babies for awhile with straight ro water... I use the water vending machines for quarter a gallon and it comes out at even 6 maybe 6.2 ph
But no nutes for at least 4 weeks and do the up potting every 2 weeks til im in 2gal smarties

 

[Gdood9]

The more lime you add to your soil the more basic your mix will become. Lime is not a buffer, humus is a buffer. A buffer brings ph's outside of neutral back towards neutral. Read up on Cation Exchange Capacity and Soil Liming.

 

[Socrates]

Thanks all! I'll use a seedling-appropriate soil mix next time, get my water pH down (probably will just use gallon-jug RO water for now), and foliar feed a little magnesium sulfate, but skip the lime for now. You all are the best, thanks for helping me to get better at this. I've mostly had success in the past but it was purely accidental, trying to step up my game.

 

[Neo 420]

The more lime you add to your soil the more basic your mix will become. Lime is not a buffer, humus is a buffer. A buffer brings ph's outside of neutral back towards neutral. Read up on Cation Exchange Capacity and Soil Liming.

Thank you.... Was waiting to see who would nail it............ I do not use lime in my mixes any longer. Humus is the key. Good compost and ewc.. Let the plant control the ph via humus and microbes.