Let's talk DIY lights


You’ve got me kinda excited! I was wondering if that might open up some options.


His tap water ppm is over 700, and he’s been using distilled by the gallon because of it. I suggested he try something like that to knock the ppm down, rather than have the inconvenience of using distilled.


You can also sneak the bigger strips into under 4 feet. They’re like 44”, so if you felt like they are a better option it’s possible. That’s one of those things where you kinda have to take a look at your space and use your best judgement. As far as the specs go, the strips are identical in performance from one length to the next. If you get down to the 280mm they cut drive current in half instead of voltage. So doing a lot of them can get kind of tricky on driver selection as there’s not a lot of big 350-500ma drivers out there.


I think I am spoiled, my water is 6.9 and 37ppm. when i mix my nutes it comes to 6.3. Doesn’t get much easier then that @dbrn32 @1BigFella


Yeah, my nute mix is 6.3 as well. But I’m in pure coco so I have to always adjust it down. About 1/2 teaspoon of vinegar per gallon does it. I suspect the nutrient manufacturers pick the right salts to buffer at that pH. Different potassium mono, di, and tri-phosphates all have different pH in solution. You pick the right amounts of each to get a certain pH of the final solution, and it has potassium and phosphate in it. Urea, nitrate, or nitrite won’t change it much. You can also use some ammonium phosphates to supply nitrogen.

Back in 1972 I just followed the tomato hydroponic recipe with lab reagents, never measured pH, and the weed plants loved it. I think it was maybe four different salts in tap water.


Hey all -
This morning when I went down to check on my plants and top them off, my light rail wasn’t turned on. It had power as near as I can tell.

I took it out of the tent, cut away the heat shrink tubes, checked all the connections. It seems to be okay. What’s the best way for me to diagnose this? How can I determine the driver is working properly?


Solids in your tap water will resist movement of the ph depending on how pure it is.


Hey, I responded on your thread. Keep me posted


I will. I’ll post any remedial action I take that works here as well so other people can learn from my foibles. :slight_smile:


It appears I have/had a loose connection with one of the holders. If I jimmy the wire I can make the light turn on and off. I put it in the holder as well as I can, I’ll just have to keep an eye on it for now.

Once I have some disposable income again, I will make sure I have extra parts on hand as well so I can troubleshoot effectively and more quickly.


No big deal. If and when you can I would try to replace that holder. I wouldn’t spend a ton of money on extra stuff, they usually hold up quite well. As with everything, there are always exceptions.

Glad you have it figured out relatively quickly! If I may suggest, try to familiarize yourself with that meter in your spare time. It will definitely be a time saving tool if you’re going to be doing more builds.


Yeah I have some big plans, including adding a breaker specifically for my grow tent, so I need to get more familiar with all things electrical. :smiley: It’s on my to-do list.


@dbrn32 i googled a question about my plants last night, and one of the links brought up that roll it up site… every other post was growers bashing each other and mostly over stuff not pertaining to grows. Saw a guy who gave advice ona topic that was 10 years old, and like 5 members jumped his case and made him feel dumb for not seeing his info wasnt going to help someone 10 years prior lol. I will stick with I :heart: GM


Exactly! There seems to be a lot of really good growers and intelligent people there, unfortunately the masses gobble a lot of that up.


I don’t mind reading through them to get to nuggets from the likes of Growmau5, who have posted there in the past. But generally I stay away from the “big” boards because there are too many people who want to treat you like an idiot for being new to this. ILGM4LIFE as far as I’m concerned.


Growmau5 probably realized that particular scenario, and I would bet I’d the reason his YouTube channel it what it is.


I have to dig through this super long thread to determine if it has been discussed, but has anyone built their own boards from the Samsung diodes similar to a QB?

I am looking at them on the digi-key web site and doing some pondering.


If you want some good ideas, check out LEDgardener website. They have several builds with the flexable strips and the hard strips too.


Nobody here that I’m aware of. The reflow process is difficult to do at home, so if you look hard enough you can find others sourcing their own boards from China.

It does seem like there have been some issues with the Chinese suppliers using substandard diodes and claiming they are top notch though. If you’re looking at going that route, perhaps checking out the photon phantom or go green boards may be an option? As a disclaimer, I have zero experience with either of them.


I have some eBay 660 nm red COBs on the way from China. I am sceptical. They were awfully cheap. I plan on getting a real XPE so I can check the wavelength of the Chinese ones. I can also check out the lumens per watt against the real one and see if they are worth running. I’ll post the results. These guys are Electronics.Alice and they advertise COBs of various wavelengths and wattages on eBay.

There is also another Chinese company on eBay claiming to deliver 10 XPEs for 19.99 mounted on stars, which is the cheapest I have found. Again, may be fake brand X or bottom bin.

You definitely want them mounted on stars or strips. Soldering all those surface-mount diodes would a ridiculously time consuming task unless you had all the equipment. Stars are easy, just a huge amount of normal soldering. Strips are even easier.