Need advice about 150 hps!!!!!!!!!

im planning on vegging and flowering under a 150 hps, 1 or 2 plants. my question is how bad will the stretch be when vegging? ive heard they stretch like crazy then i've heard if you keep them at the right distance that stretching isn't a big issue. i have it at 20 inches right now. i just don't want to stretch these little ones out. im wondering if stretching does occur..... will some topping help fill out the plants and keep them nice and bushy. any advice from first hand experience would be AWSOME. thanks

I use a 70w HPS in a 30" box. No stretching

If they're not too young 20 inches is pretty high, get it as low as you can without temps becoming an issue

I keep my 150w 3-4 in from the plants...Dont see too much stretch beyond whats normal.

I dont like topping, lst or whatever with small lights...you get so many fluffy buds 80% stem..i like to do more smaller plants with 1 cola. (sea of green..more like pond of green tho haha)