The Traveling Grower - The Struggle From the Road



Cobkit delivery came today! Maybe Thursday night I’ll have time to get to Home Depot for the aluminum angle and whatever nuts and bolts and screws I’ll need.

I ordered a spool of wire. That will be here on Friday, but if I happen to see some at Home Depot I’ll grab some on Thursday. I would expect I’ll have a good enough block of time to do the build on Saturday night or Sunday morning.


@Bogleg check thermostat wire for your house when at the big box store, for any extra electrical wire you may need. I found 18 gauge solid there. Those are some great looking flowers that will only build from here on! Nice growing!


Here’s my dumb question of the day, @dbrn32 - when you say that a light is X percentage amount efficient, what do you mean? Efficient compared to what? Is that in terms of the amount of energy consumed vs. the amount of light produced?


Yes, par Watts vs heat Watts. Your driver should be between 93-95% efficient. That means if the leds are pulling 200 Watts on the output side the driver should pull between 210-214 Watts on the input side from wall. On the leds, efficiency is amount of light put out from the diodes vs the amount of heat that needs to be pulled from the diode.

It’s one of the main reasons we don’t run the cobs at or near max output. For the sake of using round numbers, let’s say an led is 50% efficient at 50 watts but only 30% efficient at 100 Watts. So at 100 Watts you’re only getting 5 extra watts of light, but it’s costing you double to run. In this scenario four 50 watt cobs will absolutely smoke there 100 watt cobs. 100 par Watts vs 90 par Watts, and the 100 par Watts is 33% cheaper to run.

See how easily it is to bust any watt per square foot reference to leds?


Thanks! That’s very helpful. Now I can pretend I know what I’m talking about better. :wink:

While I am here a short update today. Reservoirs in both plants were at 5.62PH this morning. I added 2ml of PH Up and left them at 5.84.

I ran a little experiment last night based on a theory I have. I am wondering if the 14C water temps in my buckets is causing nutrients - in particular my Armor Si - to not stay dissolved properly. So I threw 5ml of Armor Si in a water glass and stuck it in my fridge last night. Sure enough, this morning there were little globs of silica on the bottom of the glass. My working hypothesis for why my PH is going down (in two different plants with very different feeding levels) is because of my excessively cold reservoir water (57F).

As I’ve mentioned I have a pair of aquarium water heaters that should arrive tomorrow. Assuming I see no signs from the plants that indicate otherwise, my assumption is that once I warm the water up to 65-68F my PH dropping issue will go away. We will see.

@Donaldj - can liquid nutes (in particular silica supplements) coagulate if water temps or the nutrient bottles themselves get too cold?


One last note from today: both plants have hardened off, so training is done, other than minor shift of a top here or there to make sure there is enough space, air flow, etc.

I also want to note that the last full update (from yesterday) marked the 9th day since first sign of flower - the 23rd day since I switched the lights to 12/12, and the 86th day since the plants first sprouted.


@dbrn32 - I have the COBs mounted to the heatsinks. Hopefully I did it right but it seemed pretty straight forward:

I’ll likely need a pointer or two on the wiring. As far as mounting goes, looks pretty simple since the heatsinks are all tapped and ready to go. Doing it this way seems really simple for us non-handy types. :slight_smile:

So my newb questions are how I connect the driver to the first COB in the series, and how I plug into the holders… you don’t need to answer those questions, I will go seek out my own answers today and if I can’t find an answer, then I will bug you. Thanks once again for all your help (so far) - these skills are going to get me to the next level someday!


I usually mount my cobs after I have heatsinks mounted on my frame. Shouldn’t be a big deal, just be careful as you’ll likely be moving it around quite a bit. Wiring isn’t that big of deal. You’ll want to put dc positive from driver to the positive terminal on first cob. Probably easiest to use one end or the other. Then you’ll run the negative from that cob to the positive terminal on the next cob. And then the negative from cob two to the positive on cob three. Keep following that method until you get to last cob in string only having negative terminal empty. The dc negative from driver will go the empty negative terminal on the last cob.

When you mount them. Make sure all the cobs have positive and negative oriented in the same direction. That will make all your series connections easier, save on wire, and have a cleaner overall look. Connecting the wires to the cobs should be as easy as stripping about a 1/4” off the wire and giving it a little push into the connector on holder. Once it’s in, give it a few gentle tugs to make sure it’s far enough the locking mechanism has grabbed it.

If you would like a tutorial, I would suggest the growmau5 I believe he has 7 part diy instruction. You’re probably at the point beyond the first few, check maybe 5 or 6. Sometimes seeing is better, but it’s pretty easy from here.


Yeah I am on part 5 of his tuts right now. :slight_smile:

I got confused because I have the B version of the driver, and the dimmer leads were confusing me. He’s covering that in the tuts so I think I am more or less up to speed.

I didn’t think about mounting the COBs after the heatsinks were on the frame… didn’t consider that there was a better order of operations. In any case since they are tapped and I have the screws already, I don’t think it should be too dangerous to the COBs.

Speaking off which, what size holes will I need to drill into the aluminum angle to mount the heatsinks? I am not a guy who can identify a screw size by looking at it.


Something tells me I can just go to the cobkits web site and find out the answer to my question… I’m so lazy sometimes.


B version is better for more advanced build in my opinion. So don’t sweat it. For now, put a wire nut on each of the dimming leads individually. NOT TOGETHER. You want to make sure they don’t touch each other, that’s bad news!

If you want to be able to dim it, you’ll need 100k potentiometer and a 10k resistor. Some heat shrink and spade connectors and maybe a project box or whatever isn’t a bad idea either. But we can cross that bridge whenever you’re ready.

I usually recommend a style for first build as it has 50-100% dimming capability built in. But I personally use the b version, because with the dimming leads open the driver will actually put out 105-108% of rated current. It’s like a built in free power boost. I actually wire in a small toggle switch before the resistor and potentiometer. So any time I want I throw toggle and take advantage of that extra current. When I want to dim, throw toggle back and adjust pot to desired level. Up to you if you want to do something like that.


I’m out of likes for a few, but I’m not sure on bolt size. I’ve never ordered from them. I’m sure a quick look or an email will get your answer though.


AN in particular gets a skin and does coagulate some over time but good silicate products settle more than coagulate. I also have never had GH trio form skin or coagulate so mostly about quality of nutrients used


Well, perhaps “coagulate” wasn’t the correct terminology. In any case, could cold water temps cause the silica to settle, and therefore not be available in the water, and therefore cause the PH to lower as it settles?


I answered in lab it doesn’t quite settle more it reacts with ph of water and looks like adding milk to coffee


Yeah that’s how it appears when I add it.

Well… what’s your take on my constantly dropping PH? It’s happening in both plants - not as dramatically as it was when I was in the 3.5ga buckets, and I stay within the proper PH range between top offs (normally, over Christmas I had an extra day away from the plants and the GL was at 5.3 when I got to it), so I’m not overly concerned. It’s happening in both plants almost identically right now.


How does your ppm swing look? is it raising lowering to coincide if you are growing in hydro a notebook is your friend :wink: growing from clones and mother even more so


It’s gone down or stayed the same. I have had the GL at around 800 PPM and the SSH at around 1100. They are in second week of flower (at the end of it). Also, the plants look fine.


some ph drift is normal it is actually the result of plant interacting with nutrients taking this leaving that and the interactions of remaining nutrients ph has a range not a fixed number if your ladies are healthy and feeding drinking there should be some movement in ph and ppm as well as water levels. Drastic ph swings bad gradual good


Day 10 of flower. Day 24 since switch to 12/12 lighting. Day 87 since first sprout.

Everything seems okay this morning in spite of my water being under 57F. The fresh water in my buckets that’s been in them for the past two days is at 10.2C!

In any case, the PH in the GL only dropped a little (5.77) and the SSH dropped to 5.65 since yesterday. I topped them off with PH 5.8 water that had 3ml/ga of Armor SI in it (PPM 129). I left them at 5.84 and 5.88 respectively. The GL PPM after being topped off with plain water was 744, and the SSH was 1050.

Yesterday after I topped them off they were at 840 and 1200 respectively. It sure looks to me like heavy feeding has begun. I am going to start bumping up the PPMs slowly.

Here they are today: