Do I need a skimmer?

I grabbed a 175W MH ballast from a light at a bank that was being redone, wired it to a mogul socket and a plug/cord, screw in the bulb, plug in the wire, it lights

The tank I got from a local reef club member has a 12" high canopy/hood and I mounted the light in there, works great.

On another note, I'll probably go ahead and get a skimmer. There is a Bak-Pak and a remora available locally for good prices, we'll figure it out

 

Make sure you replace your bulb with a better one. The kelvin temperature is probably way off. Also make sure you have no splashing below the halide. Commercial lightings is not water resistant.

 

Most reefers run on a protein skimmer and a fuge + a UV, if you don't have a skimmer i will require alot more work. As for live stock Damsels are aggressive and so are maroons, i have both they fight coincidentally. damsels are aggressive and your going to have 12? if your maroons are going to have anemones your going to need lighting T5 would be best, this is mine, I highly recommend it
AquaticLife T5 High Output Lights, Lighting | Pet Solutions

 

It's possible but I would start with a skimmer and as you learn more remove it if you have another system to remove nutrients. Skimmer is probably the simplest and best way to remove nutrients.
If you put food in the tank there needs to be a way to export the nutrients.

Skimmer
Algae scrubber
Vodka/carbon dosing
Water changes ect.

If you think you're going to do big water changes on a 300 gallon with high nitrates and keep the water good enough to keep corals(especially SPS) ... I don't really think it's a good idea. To do a 100 gallon water change is going to cost you at least $25 in salt. Then your nitrates will creep back up in a couple weeks and you'll be right back to doing another water change. A skimmer will remove nitrates by removing waste and nutrients before they have a chance to break down into nitrates. A refugium with macro, algae scrubber, and carbon dosing will neutralize the nitrates and phosphates. So it's best to have a mix of the two.

 

I have a 14k reef bulb, i basically gutted the commercial fixture to get the ballast and mogul socket, then mounted these for my situation and popped in a reef bulb.

I also think the MH will be better than than T5HO for an anemone and corals. I think I'm going to get some frogspawn for the clown to host.