HPS Autoflower Grow Questions

Im just starting my first Autoflower grow(3 auto AK47 seedlings)(8 diesel ryder seedlings), and I have a 400 watt HPS light.

My questions are, can I use the 400 watt HPS from seedlings? or am I going to need a MH conversion bulb?

would I still have a good yeild if I used the 400 Watt HPS from seedlings?

Since I wont be veging them at all under a MH light, kind of tight on cash, iv been layed off, so I cant really afford a MH conversion bulb since they cost around 100 dollars.

Thanks in advane, iv been looking all over for some information about this, but I gave up and decided to start a thread.

Autoflowers pretty much skip right through the veg phase and straight into flowering. Use your HPS all the way through, lemon....no worries mate. Those AK's are going to put out BIG ODOR.

HPS @18/6 and you'll be cutting them down in 70 days