HELP! Cooling 2x Mars Hydro 600 in a 4x2x5 grow tent

Hi,

Doesn't everyone love it when you buy all of the right equipment, only to find sh*t doesn't work? Well that's how I feel after buying the perfect grow setup for my living situation only to find out I can't keep the grow area cool enough for the spec'd out 2x LEDs

Problem: LED Grow Lights vent the heat they produce out of multiple ports surrounding the sides of the lights making it difficult to isolate and contain. The end result is heat being exhausted into the grow area before eventually being evacuated by the air filtration system.

In my situation, running 2x 600w LED grow lights caused my tent to reach temperatures exceeding 90'F at times, which turned many of my plants yellow, stunted, and a whole slew of strange nutrient deficient like problems with many of the older leaves on each plant, but turned out to be heat stress.
I've tried running my air filtration system at a higher rpm, but the noise is too loud for my living area to go unnoticed. At the moment, I'm using a 240cfm air booster at 70% speed using a ven-tech controller. Any higher and its just too loud, but DOES obviously help drop the temperatures down when running at 100% speed. So, I then tried reducing the lighting down to 1x 600w LED, and found I can get temperatures to hover around 76'F, which is great, and the plants respond immediately to the drop in temps. The issue is, running a single LED doesn't seem to cover the width of the 4ft tent; it's output at any height is more or less 3 to 3.5 feet causing some slight darkness on the outer edges.

What I'm here to find out is if anyone else tackled a problem like this in a smaller grow room. I wish I'd had bought the 7 or 8 foot version of the tent so I could raise the 2x LEDs higher up to contain the heat, sure losing some lumens, but not 50% like I am now running at 1x LED.

thanks

Add another fan to your setup. One for exhaust and one for intake.

Personally I'd try to find larger fans. Your jus not moving enough air through the tent fast enough to get rid of the heat.

Carolina Dream'n said:

Add another fan to your setup. One for exhaust and one for intake.

Personally I'd try to find larger fans. Your jus not moving enough air through the tent fast enough to get rid of the heat.

Click to expand...

Is there a way to do it quietly? Like, do larger fans (8" being the largest my tent supports) with high cfm running at a slower speed be quieter than my 6" 240cfm at full speed?

PrinsesS said:

Is there a way to do it quietly? Like, do larger fans (8" being the largest my tent supports) with high cfm running at a slower speed be quieter than my 6" 240cfm at 3/4 speed?

Click to expand...

I doubt they will b quieter to be honest, but they will do a better job. I doubt they would be that much louder.

Adding another 6" fan, for an intake, reduced down shouldn't add any more volume.

Hello just a suggestion, can you send the 600w back and get x2 300w of the same light, they would be easy to position and likely emit less heat.
I tried a single 600w Mars hydro led in a 2'x4'x5' and it was at 97 degrees farenheight ,even with all the passive intake open and a 4" exhaust Ventech and a 6" circulation fan. So I switched to CFLs for the less heat and noise.

your in a 4x4 tent? how high is your ceiling? and also your saying the Mars Hydro 600w .. which unit is that specifally ? from the pro series or series 2?

EDIT: just realized you've already given your ceiling dimensions. lmao. yeah im surprised you tried to put two 600w LED's in such a small space .. only 2x4 wide and 5 ft tall? i know you probably expected very cool running LED's but still for that space you were cutting it close. im curious to know which of the mars units you have? im surprised it only got up to 90

I was in a similar situation as you. My grow space was 3x2 and i only had a mars 300w (140w actual). I ordered a second light shortly before finding out that i would need at least a second mars 300w for flowering.

Well when i had just the one, the temps were never an issue and they never got above the mid 70's. Once i added the 2nd light it was damn near impossible to suppress the heat... I hadnt really tried to be honest i had a fan to give the plants a breeze but heat expulsion was a distant 2nd as to why the fan was there in the first place.

I dont have the same size and noise restraints as you do. So i put them in the floor of my bedroom closet. That instantly fixed a lot of my problems.


I think the solution to your problem is to get a different tent. Which wouldnt be a bad long term thing any way... I mean... By time you subtract pot space and light fixture (negative hanging space) youre lucky of you have 4' of empty space. Take away half of that because your plants need to be 2ft from the light, and youre talking about growing 2ft plants.


Sure there are a lot of autoflowering short strains out there that you can work with and make happen... But you cant honestly tell me that the thought of growing some beautiful chocolope doesnt give you a lady boner

thothmegistus said:

your in a 4x4 tent? how high is your ceiling? and also your saying the Mars Hydro 600w .. which unit is that specifally ? from the pro series or series 2?

EDIT: just realized you've already given your ceiling dimensions. lmao. yeah im surprised you tried to put two 600w LED's in such a small space .. only 2x4 wide and 5 ft tall? i know you probably expected very cool running LED's but still for that space you were cutting it close. im curious to know which of the mars units you have? im surprised it only got up to 90

Click to expand...

Yeah its 4x2x5. I decided I'll finish my current grow with it; too much $$$ invested in everything, and christmas just passed, so maybe in the new year I'll ditch this tent for one that's 7 or 8 ft high instead. I do like the compactness of a 4x2 tent mind you; they fit up against walls nicely without taking up much room. The mars hydro 600w unit looks like the one below (although that might be a picture of the 300w model). It's got 5w LEDs instead of the older 3w LEDs. I honestly can't tell what's different about this model and the newer black ones without reflectors. I'm pretty certain they're the same sh*t

On the bright side, I did manage to get my temps down to 77'F~84'F this past few days. Being frustrated with only using 1 LED, and seeing less light penetration, I took everything out of the tent and tried another setup design, this time with both LEDs raised as high as they would go in the tent. I managed to squeeze the 6" carbon filter and lights into the upper most part of the tent leaving only an inch of airspace between the LED intake fan and the carbon filter itself. I then opened all 4 intakes on my tent, blocked off the heater duct in the room the tent was in, and opened a window a crack to let the winter air in. Afterwards it was just a matter of increasing the intake fan speed to create enough negative pressure to draw the cool air in, which of course ended up being really loud so I adapted a DIY muffler box to the exhaust duct using a box, filter, and some insulation. Surprisingly, the isolated room is being heated by the tent to 75~80'F even without furnace heat, and with the window open a crack.

All of this seems to be keeping the tent cool, but there are times when the sun hits the window and the tent will heat up again to 84'F (not bad, but not great). I do have to close the window at night or the room will freeze, that's the only major downside. Being that I have to go on vacation for a week during my grow, I might have to drop down to 1 light again in order to close the window while I'm away. It's a small trade-off i guess.

You can keep the one unit running with controlled temp correct? Install a light rail to complete this round. Then if you upgrade your space IE: new tent or whatever the situation requires, you'll have a great light combo and a rail to maximize space in you new area. In my experience you can never go wrong with owning a light mover. I've loved mine for years. Hope that will help good luck.

thothmegistus said:

your in a 4x4 tent? how high is your ceiling? and also your saying the Mars Hydro 600w .. which unit is that specifally ? from the pro series or series 2?

EDIT: just realized you've already given your ceiling dimensions. lmao. yeah im surprised you tried to put two 600w LED's in such a small space .. only 2x4 wide and 5 ft tall? i know you probably expected very cool running LED's but still for that space you were cutting it close. im curious to know which of the mars units you have? im surprised it only got up to 90

Click to expand...

I'm using a pair of 2nd generation Mars 600s like the one below:



It uses 5W LEDs instead of 3W like the 1st gen ones, and were a steal of a price, but pump out a lot more hear than I had anticipated. I'm also not sure what the difference is between these and the newer black ones, except the shape to be honest.

In the end, I got frustrated with the lack of lumens and light penetration when I dropped down to only 1x LED, so I removed all of the electronics and reinstalled everything in a way that both lights are as high as they can go in the tent; almost butted up against the air filter with a small gap for airflow. This in conjunction with blocking the heater vent, and opening the window a crack in the surrounding room, SEEMs to be working. I'm now seeing temps hovering around 77'F~84'F depending on if sunlight is warming up the room any further. I might duct air from the outside into the grow tent but I'm worried it'll look bait to have ducting visible in a window during the winter time. I also need to make sure the window or intake is closed when the light is off or the whole room will freeze. It's a small inconvenience for now, until I can come up with a better solution. In the end, I got both of my lights up again in the tent, and the plants aren't showing any negative reactions yet. I'm definitely going to get an 8 foot tall tent for my next grow however.



My next task is to build a muffler for the exhaust because I now have to run it at higher rpms causing excess noise