While I'll agree with about 90% of that, salt is salt. many, many tanks are using IO, and succeeding. The trident/apex combo, while nice and certainly a luxury item is not needed either.the salt that works best that's a bit of work is the Red Sea salt (blue bucket) you will want to buy the Red Sea CA MG and All powder for all three 60 bucks and it will last a very long time. the levels are a little low in the salt mixture so you will have to add some of the powder additives when mixing the salt. Should target for 8dkh 450ca and 1350mg. Also If you really want to have good experience with sps you have to do a lot of testing and have constant levels. I would suggest staying away from across till you get some more experience other wise you will be tossing money away and have a lot of frustration. If you get really serious about having acropora I would suggest buying the seneye reef monitor its a lower priced par meter. You will want to get a Hannah checker ULR Phosphate, check your alk frequently. and test your ca and mg every few days. Especially on that size of tank. I do recommend the Neptune trident combo as it will test daily. Sounds like your Macroalgae is sucking up to much nutrients also.