Why have some of my plants stretched whilst in flower??

Yo guys, this is probs my 6th grow now, only started topping last grow, and the same thing happened last time aswell....

Basically, ive got 4 power plant and 1 white widow, my white widow was topped above 3rd node in veg, is in the centre under my adjustawing and is growing nice and short and bushy with fat buds appearing..my power plants are different, 2 of them have been fimmed, with great results, nice and bushy with shitloads of tops but the 2 at the back i topped em above 3rd node whilst in veg and they seemed alright and quite bushy and as soon as i put em into flower theyve gone crazy and gown so tall its ridiculous, im not sure why, theyve just stretched massively.

The bud sights still look ok, but i just want to know why they grow/stretch so tall and how to avoid it. Just seems every time i top a plant it still just stretches up really tall when in flower anyway, instead of bushing out wide like it's supposed to. Temps are averaging about 29/30degrees celsius but this shouldn't make em stretch should it? Plus my other plants (fimmed ones) are doing fine, although even one of them is a lot taller than i expected....

Any ideas??

Oh, and my adjustawing is never more than 36inches away either so i dont think the light has much to do with it!

36 inches is a long way! I run my 600w hps at about 18", getting down to 13" in winter with a light shield.

My 600 is about 18" . Cooltube setup.

i keep my 600w w/cooltube at 12 inches. the plants can(and often do, space is at a premium in my grow so every little inch counts) get to within about 6 inches in winter. also in a way you kind of already answered your question of a way to stop it from happening in the future- fim instead of top them, you said the fimmed plants were not nearly as stretched. some selective lst is always helpful when controling stretch too.

Ah shit I meant 36 centimetres not inches. Its usually really close to the plants but they still stretch. Fuck it though, fim all the way next time! Fim for the win!