I'm having problems with my poison necro(pvm).He just wont survive very long.I'm using full trangs set with a 2/2/47 deaths web,1 soj,1 ravenfrost,Nats boots(lol,i need the resists).On weapon switch I'm using Blackbogs sharp cinquedas,and a hommy.My stats are enough to use gear,and the rest in vitality.Btw,he's only lvl 67.Poison nova is 4.5k over 2 seconds,and dagger is 11k damage over like 12 seconds.Even with all my points into vitality he only has 700 life.I need a pros help,like maybe you,Frater.Or anyone who knows anything about poison necros.

You pretty much answered all of your questions within you post.
1) He is only lvl 67.
2) He is using Trang Oul (sucks)
3) He is using Nat boots (suck)
4) No CTA

Necs have low life by default and a lack of CTA means that he will be very lacking.

Throw away Trangs, it is not even worth pgems.

Get gear that is nowadays standard, i.e. Enigma, Shako, etc.

Browse around the necro sections, there are plenty of threads on bone necs.

Ok,guys.Thank u very much for your valued opinions.Thanks for the offer Joshy,but im east nl.And I'm not really poor,I'm necro challenged as I've never built one before this poison necro.So the basic idea is to scrap trangs and use enigma(i also have a bramble(40/20),shako,Hommy,deathweb,and some fcr gear?Oh yeah I also have a 6 bo ettin cta and a low spirit monarch(on a mule).As far as boots go,i have a pair of treks or a pair of waterwalks to choose from.I was just using the trangs for the -poison resistance from the green bonus on the shield(24%)with the -poison resistance from deathweb(47%),and the -poison resistance from LR(56%).Again,I say thank you very much eveyone,for the better ideas.

Keep the Trang gloves for the fcr and the added poison damage. You will probably need a act2 tank merc as well. Eth Reapers Toll and holy freeze aura with tele and you should be fine. I always put one in clay golem and then you own most bosses. Add a poison facet to your weap as well!

My new setup will be(drumroll please)shako with poison facet,loricated bramble(40/20)arach belt,Death's web weapon(2/2/47) with poison facet,um'ed hommy,soj,ravenfrost,trangs gloves,sandstorm treks,Mara's amulet(or any good pnb ammy with resists),and a torch when i get one.For weapon switch,I'll use my cta and spirit and just forget about poison dagger altogether.Hopefully All this gear will help me survive a bit better.Thank you everyone.Also right now my merc is an act 2 normal defiance merc with shaftstop,crown of thieves,and demon arch spear.I know i need a better weapon for him,but demon arch does have 12% lifeleach.

I think you should buy a nm act2 merc that has holy freeze aura and I don't know if you need that raven or not. It sounds like your a castor, not melee? Use a bk or soj or fcr ring, depending on what your necro lacks.