water temps and PPM questions in DWC grow

[lincon1231]

Im starting my first grow in both Coco and DWC
Due to my research water temp should be kept around 20C, 60-65F
I live in an area now temp around 5-15C, 41-59F
So the water will get really cold during the dark I suppose?
it's that gonna be a problem?

Another question
According to my FoxFarm hydro nutrient feeding schedule
The recommend ppm for seeding is 490-630.
but i also learn that not to use any nutrient during seeding from research
Should I use any?
Also any tips for first DWC grow?

Sorry for the poor english, not a native speaker

[dontknownuttin]

Think Aquarium heater set the temp. it holds it cheep on Amazon

[DoctorJohnson]

20 C might slow growth a little (or it might not) but it will not be a big problem. (The problem is usually water temperature that is too high.) You could add an aquarium heater as DKN suggested, but be careful to not boil your roots! Me, I would just leave it alone.

> i also learn that not to use any nutrient during seeding from research
Don't believe everything you read! You can give a seedling low concentration fertilizer from Day 1, but I would suggest half the number you quoted--200 to 225 PPM or so.
Lately there has been a lot of folklore that you should not give nutrients to seedlings, almost as if fertilizer is toxic to a seedling, but that is incorrect. Yes, the plant can use nutrients stored in the cotyledons, but you do not have to force the plant to use only its stored food supply. The reason the plant grows a big root first is to get nutrients, so give it something to eat! It is getting nothing from the water or coco!

[lincon1231]

20 C might slow growth a little (or it might not) but it will not be a big problem. (The problem is usually water temperature that is too high.) You could add an aquarium heater as DKN suggested, but be careful to not boil your roots! Me, I would just leave it alone.

> i also learn that not to use any nutrient during seeding from research
Don't believe everything you read! You can give a seedling low concentration fertilizer from Day 1, but I would suggest half the number you quoted--200 to 225 PPM or so.
Lately there has been a lot of folklore that you should not give nutrients to seedlings, almost as if fertilizer is toxic to a seedling, but that is incorrect. Yes, the plant can use nutrients stored in the cotyledons, but you do not have to force the plant to use only its stored food supply. The reason the plant grows a big root first is to get nutrients, so give it something to eat! It is getting nothing from the water or coco!

thats really helpful
thx man

[UrbZ]

I agree here. DWC and coco are the same in regards to food. Soilless applications need more food at the start compared to soil. Plants dont get all the goodies they need just from cotyledons they also get it from the soil its planted in. When using coco or dwc there is no immediate food access like in soil. I would also say start at about 175-200 ppm of food and watch the reaction closely. You will notice quickly in both coco and dwc if you fed too much. The food is almost immediately picked up by the plant as there are no buffers to interfere with the absorbtion.