BeyondGroove said:

Hey all, new grower here. I’m trying to start my first indoor grow after having a reasonably successful first outdoor grow last season, but running into issues.

Setup:

-grower’s choice tangerine dream autoflower seeds
-2’x4’ Vivosun grow tent
-vivosun vs1000 led light, suspended 30” over seedlings, 18hr on/6hr off schedule, lowest light setting
-in line exhaust fan with carbon filter, turned on when light is off 1-2 times a week
-2 small hanging fans, one small oscillating fan on floor of tent
-seed mat on 24/7
-humidity dome, vents slightly open
-PUR filtered tap water, left to sit out overnight to allow chlorine to evaporate, ph’d to ~5.7
-starting sprouts in rockwool cubes
-cube prep: soaked overnight in water, adjusted ph to ~5.7 periodically until stable
-additionally soaked for 2 hours in Fox Farm seedling level nutrients at 1/4 strength (big bloom and kangaroots), ph’d to ~5.7, squeezed lightly to remove excess water before planting
-average temp 70-75
-average humidity 75-99%
-misting dome/tray 1-2 times daily
-misting seedlings once every couple days

I germinate the seeds according to supplier instructions using the paper towel method. I plant the sprouts in the cubes about 1/4“ deep and pinch the cube surface lightly to cover. They usually pop up after a couple days looking healthy. When the seedlings are about an inch high and have their first set of serrated leaves come in, they seem to stop growing, develop brown and yellow spots, and slowly die off. I’ve tried soaking the cubes in plain distilled water, ph’d filtered tap water, with and without the nutrients, all to no avail. I plan to transplant the seedlings into 2 gal air pots filled with Happy Frog soil when the roots start coming out of the bottom of the cubes, but haven’t gotten that far yet.

Any pointers? Thanks in advance for any advice!

Click to expand...

If you are going to plant them in soil, just plant them in solo cups of soil. I dont like rockwool personally.

I agree with goodshit97 I dont like rockwool cubes. Just haven't had good luck with them. I start seeds in straight coco. Also I wouldn't feed nutrients until they have 2 sets of nodes. Up until that point mother nature gives them everything they need. Kind of seems like they are burning,whether from lights or nutes, I'm leaning towards nutes. Also those cubes look a little dry, Another reason I dont like rockwool it dries out so quick.

In any soilless medium you feed from day dot.period. if it was outdoors in the ground then yes mother nature can supply what’s needed but there’s nothing natural about growing rockwool cubes or coco/coir.I don’t know the ppm of the nutrients used so I can’t help with that apart from I fertigate the coir prior to transplanting feed around 100ppm from the start..tips don’t use a humidity dome or distilled water….I agree with goodshit97..if you growing in soil ,start in soil or a soil for seedlings to get them going…

This is what I meant when I said mother nature. The plant feeds itself for a little while from the cotyledons.​

cotyledon​

plant anatomy
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cotyledon
cotyledon, seed leaf within the embryo of a seed. Cotyledons help supply the nutrition a plant embryo needs to germinate and become established as a photosynthetic organism and may themselves be a source of nutritional reserves or may aid the embryo in metabolizing nutrition stored elsewhere in the seed. Angiosperms (flowering plants) whose embryos have a single cotyledon are grouped as monocots, or monocotyledonous plants; most embryos with two cotyledons are grouped as eudicots, or eudicotyledonous plants. The number of cotyledons in the embryos of seeds of gymnosperms is highly variable, ranging from 8 to 20 or more.

Function​

Dicotyledon
Until it becomes nutritionally self-supporting, a seedling depends upon reserves provided by the parent. In angiosperms these reserves are found in the endosperm, in residual tissues of the ovule, or in the body of the embryo, usually in the cotyledons. Since reserve materials are partly in insoluble form—as starch grains, protein granules, lipid droplets, and the like—much of the early metabolism of the seedling is concerned with mobilizing these materials and delivering, or translocating, the products to active areas. In some seeds (e.g., castor beans), absorption of nutrients from reserves is through the cotyledons, which later expand in the light to become the first organs active in photosynthesis. In many monocots, the cotyledon acts as a special absorbing organ to mobilize the reserve materials and withdraw them from the endosperm; e.g., in grasses, the cotyledon has been modified into an enzyme-secreting scutellum (“shield”) between embryo and endosperm. When the reserves are stored in the cotyledons themselves, as is common in many eudicots, these organs may shrink after germination and die or develop chlorophyll and become photosynthetic. Whether cotyledons help absorb nutrients from the endosperm or store the nutrients themselves, these embryonic seed leaves do not usually persist long after germination.