Cobs and spacing

[Jp12345]

Hi guys

I have 2 grow setups both for flower from clone and both 1500mm x 1100mm.

36 plants per site at 18" tall single cola.

I am switching from 1kw hps setups to cobs.

I have 12x cobs running at 75w each (citizen 3500k clu048) with a tested ppfd at 12" of 920 centre and 603 outer edge 1ft2.

I was going to run a 4x3 setup of cobs in one 1500mmx1100m area but thinking that's overkill and could pos split the cobs 6 per site, is that going to me enough coverage?

Cheers
J

[GMO]

This is a really tricky question tbh bud

you wanna aim for an even spread of 400 ppm at about 20-24 inches in my view. this wayy you can use the light system full cycle. when moving into flower the PPF around 12-18 inches should then be 600-800PPF which is kinda on the high side anyway as we aim for 500-700 for grows that arent using additional CO2

i hope this helps bud

[Jp12345]

Hi GMO

Each 75w gives a reading of 711 at 18" centre and 407 at 45cm spread.

So if I ran the cobs in a 3x2 format to cover 1500mx1100mm including cross over from each cob, would that be a decent coverage for flower?
I won't be using co2

[GMO]

Hi GMO

Each 75w gives a reading of 711 at 18" centre and 407 at 45cm spread.

So if I ran the cobs in a 3x2 format to cover 1500mx1100mm including cross over from each cob, would that be a decent coverage for flower?
I won't be using co2

yeah man, with the above info id say spacing them like 45cm from the center of each cob in the grid you mention should be really well covered. i dont think there is exactly an ideal atm so it could be worth thinking about sliding mounts rather than fixed mounting or even indivifially hanging them if you can be bothered so you can really cater the light height to where you canopy is

[Jp12345]

Awesome. In practice it would work out that each cob would cover a 50cm square and hopefully the cross over from 2 cobs in a row would boost the ppfd in the middle of each cob to give an even spread with an average of 520+