First grow, don’t understand why these won’t work

Hello everybody! I will be asking a lot of questions throughout my grow, I don’t even know if I posted this in the right thing lol but I found these at the local hardware store on clearance and I don’t understand why I need a ballast…

Because HID bulbs like MH and HPS require a ballast to regulate the current sent to the bulb because the bulbs don’t have a regulator built into them limiting the current.


welcome to the forum. its alot of great guys here that will gladly assist with all of your questions. i also had and still have alot of questions and someone always answer them so u are in a great spot.

1 Like

So obviously I would need 2 ballasts for 2 bulbs would they work in bowl reflectors… I don’t have a ton of space not sure exact specs but will put pictures up here soon… so I could purchase ballast from amazon or online anywhere?

@gatekeeper thank you for the warm welcome !


A ‘ballast’ typically converts household current and voltage into (usually) high voltage DC. If you tried to run those in a normal light fixture it either wouldn’t work or would blow the bulb, depending. I’m surprised the socket is the same as a light bulb, frankly.

They make double-ended fixtures. Also those lights generate an enormous amount of heat so you will need a cool tube to house in along with separate fan and exhaust.

1 Like

I put them In the bowl reflector waited until the lights turned on and they just didn’t turn on I read they take a couple minutes to turn on, then read about the ballast lol. but my space is about 44”x25” not sure about depth, but would 1000 watts be to much I have 2 lights I actually found a lot target they are called par38 grow lights and have a spectrum that range from 400-700ppm I have 2 of those and 2 cfls in bowl reflectors with a little fan and temp doesn’t go past 78 degrees

You need somewhere around 400 watts of actual light for that space. I just put that up as an example.

I’ve been looking at the vivosun 4” inline fan but curious I would just need to hang it connect duct drill a 4” hole on top (back left corner) for the duct/exhaust? I’m new to this and have so many questions

It says that these par38 have 90 watts each I have those 2 plus 2 cfl equaling 100 watts each… I’m going to change the lights just looking for not cheapest but not most expensive route… again will post pics in about an hour or so

They’d work in any reflectors you can hook up the supplied socket to. the 175 watt MH is not really popular in growing so the ballasts you will find for it are more of the industrial parking lot light type, personally I wouldn’t waste the money. Your 90 watt par38 bulbs are really 15 watts. You want to rethink your whole light setup.

UPDATE: alright guys I ordered some new equipment

Now I have a few questions about the air cooled hood… so how exactly am I supposed to setup the filter duct fan to the fixture ?

@Hellraiser I believe I saw something you posted in a thread of a simple setup of what I’m trying to do

I have the carbon filter -> ducting -> air cooled hood -> ducting -> exhaust fan pulling air (sitting on top of tent) -> ducting -> somewhere else.

In one tent, it’s going out a window using an ac window exhaust kit and in another, it’s going thru a hole I cut in the ceiling to the attic.

Here you see the carbon filter feeding into one side of the air cooled hood and the other side of the hood going out the tent roof hole to the exhaust fan on top (outside) of the tent.

That is beautiful and exactly what I am talking about !!! Also I don’t have to have exhaust to attic or out window do I ? I have a 2x4 closet space that I keep the door opened a tad maybe just blow exhaust out into room?


With only 400 watts just blowing it out into room should work ok.

Alright and if not I’ll make a joke through the ceiling in closet and vent through addict, anyways I have a question on another post I’ll tag you in

1 Like