Algae help... idenification?

I have a 75 gallon tank with two tomato clowns, firefish, bue hippo, mangerine goby, choco starfish, and crabs. 40-50 lbs live rock. 2 inch deep sand bed. new 15 gallon sump. and a red sea prizim skimmer. I have a red and brown algae growing in my tank. I Finally got it off my sand bed. but its all over my rock and always on my glass. It seems like its brown at first and eventually turns red. I have looked into cyno. skim like crazy. do 20 percent water changes every week. and i still see no improvement. any ideas would help.

 

i do use tap water.. but i have no chlorine, nitrates or any of that crap stuff in there... im not sure about metals tho.
nirtates are a little high. at 30

 

are u still cycling? the brown stuff could be some diatoms and as for the red stuff maybe cyano? excuse me if i'm wrong but i was never the best at algae ID lol. you'll probably want an ro/di unit; i'd recommend spectrapure

 

Its cyano bacteria. You need to reduce the nitrates and test for Phosphates. If you are using tap water I am sure they are pretty high as well. Also thats a large bioload you have so I would reduce feeding to every two or three days. Increasing the size of your water changes might help but if you are using tap water the bad stuff will come in just as fast as you siphon it out. Also adding Granular feric oxide to the media chamber in your tank will help. Be patient and vigilant it will not just dissapear overnight.8) Manual removal with a large turkey baster will help as well. Take Saltwater Guys advice and get yourself a good RO/DI unit or it will be an uphill battle for you.

 

still recommend ro/di water and sorry about the cycling question; i was just identifying algae XD. but please get an ro/di unit; if you don't you'll have algae in all colors of the rainbow... the bad kind i should say. I would know; i went through it, all that disgusting red, green and brown stuff on my sand and tank walls

 

i have tested for phosphates about a week ago, it was barley detected. this tank has been up and running for about 6 months now, When i feed i do it once a day and everything left uneaten is taken out of the tank. I have looked into a ro unit. but very expencive. Could i use a brita or another form oof filteration other than R.o water.. somthing that hooks to the tap. I think 20 percent a week is already enough of a water change

 

Tap water filters only remove chlorine and a few other volatile organics, but no nitrates. The reason you have low phosphates is the algae is consuming them all. The only way to defeat it is to save and get an ro/di unit. Water changes do no good when you are putting the same chemicals in as you are taking them out. You are exchanging bad water with bad water.

 

+1; even if u do a water change all the metals that the tap has are just going back into ur tank cuz the water isnt purified

 

I was not only refering to uneaten food. Eaten food turns into Nitrates. Anything that poops will contribute to the Nitrate level. That is why I recomended once every two or three days.

 

I use the 5g jugs and get ro water from the store. I'm going to get a filter soon, but until then I hall water.