Start of Week Five

 The start of week 5. Harvest in 5 to 9 weeks:

 The tallest plant in pot #4 is 28" tall. The plant in pot #1 is a dwarf, same age and conditions as the other three plants but small and not getting bigger. The three "normal" plants could double in size before time to harvest.

The three Coco Coir plants have been moved to the side of the tent so they could receive necessary DLI.

H2O Transfer Problem

 My auto Water Transfer from holding tank to Central Feed tank has worked like a champ until this AM, four hours before leaving for a two day trip. It never fails to happen when there is nothing you can do about it. It could be one of three things, in order of likelihood: Not enough "Head Pressure" (water in holding tank too low), kink in feed line between holding tank and Central Feed tank, or something blocking the Central Feed tank's float valve. 

I expect it is likely a slight kink combined with lower head pressure. For this trip I will top off the Holding tank and will make sure there isn't a kink in the feed line. Worst case: The feed from holding tank to Central Feed tank stops again is no water from Central Feed tank. Each of the Grow tanks holds ~2gal of water when the Central feed tank's water level is at the top of the "stand pipe". The four plants are currently using ~one gal/day.  So worst case: No water from holding tank for two days, the grow tank's water level goes down a gal., no a biggie for a day or two.

It is still a concern and something to worry about while we are camping.

End of Week Three

 The RDWC plants are ending week three, the Coco Coir plants are starting week three. Coco Coir is kinda like soil but is also a little like hydroponics in it has no nutrients and it does not buffer as well as soil. Like soil, to monitor nutrients and pH you need to measure runoff where with hydroponics both measurements are direct.

Other than time the most important factors with a hydroponic grow are EC, pH and DLI. Water temp is also important to prevent root rot but with a water chiller water temp is just something to note. EC or electrical conductivity is a measure of salt content. EC is a Goldilocks kinda thing it needs to be enough but not too much, too low and the plants do not get enough nutrients, too high the plants do not get enough nutrients because they are locked out. Cannabis likes a slightly acid environment (pH 5.5 to 6.5). I like to vary the pH slightly as some of the nutrients absorb better at the low end, some at the high end. The third factor is the Daily Light Integral (DLI), a measure of how many photons the plant receives over a 24 hour period. Photone makes a good phone app for measuring DLI.

This AM the EC tested 1.37, target range 1.3 to 1.5, pH tested 6.3 and DLI was adjusted to 51, target range 45 to 55 DLI. I added 10 ml of pH Down, 50ml of nutrients and will re-test EC and pH this afternoon.

  The beauty of hydroponics is with good test equipment all three are easy to dial in and keep in optimum range and once dialed in the grow takes care of itself. 

BTW, I have a "dwarf'" plant in the #1 bucket. It is the same age, same grow environment, same lights, and nutrients as the other three but as you can see about a quarter the size of its sisters.

02-02-2025 Start of 3rd Week

 Tent 77F     

Water 67F

EC 2.0

pH 6.3

EC is still a little high but coming down, EC at this stage should be between 1.3 -1.5. Plants look good over all. Plant #2 has some evidence of early over heat on lower leaves and Plant #1 is a dwarf. Plant #1 has had the same feed, light, and conditions as the other three, it is just going to be small. Plant #4 has huge Indica leaves and a main stem to go with them.

An Overview of the tent, 4 RDWC pots with 3 fabric pots with Coco Coir, all plants from ILGM LSD Auto seeds. The RDWC plants are starting their 3rd Week, the  three Coco plants are a week behind; In a couple or three weeks when the RDWC plants are getting big the Coco  Coir pots will be moved from the tent to the side area and WX permitting maybe outside.
 

Pot #2, #3, and #4 are all healthy. This is Pot #2

Pot #1 is a dwarf, same start, same water, pH, and light, just a very small plant:

Click 'em to big 'em.

Lights have been changed to a Flower setting Red and White full power, Blue about 60%. The last three weeks I will add UVB lights for 2 to 3 hours a day. Now it is just keeping the EC and pH where they need to be and watching 'em grow for 70 or so days.

01-24-2026

Tent            77F @ 0100 MT

water           68F

EC               1.94

pH                6.4

DLI            35/18

Added 5ml pH down, will check pH this afternoon.

I'm working to bring pH < 6.0 for a couple of weeks then slowly back up to < 6.5. I'll hold DLI for another week then take it to between 45DLI and 55DLI. and hold it there until the last couple or three weeks when I add in 3 hours of UV/day and take DLI back under 30 DLI. EC is slightly below target I expect Sunday's feed will move EC to target or slightly above.

Tent temp stays high during daytime ambient temps and I'm seeing some slight "tacoing" of leaves but there isn't much I can do to bring tent temp down other than a bigger AC unit or less light output.

Water temp is perfect. Last season's grow suffered from high water temps which led to late grow root rot and the plants died before full maturity. Water temp control is the biggest problem with a DWC setup. Because a RDWC system has a central water supply a "water chiller" can be added to the system. Root Rot should not be a problem this year.

 

DLI Chart

 

2025 Grow Veg Week 2

 Getting the tent dialed in:

Tent Temp     84F

Water Temp   68F

EC                  1.83

pH                  6.8 (added 5ml pH down)

DLI                35.3/18hr

 The RDWC plants are looking strong, the Coco Coir plants are about a week behind and are looking OK but have not started growing. The Coco Coir holds water very well, last water was a week ago and they are still wet enough but they need feed and pH adjustment so they will get some water and feed today.