Algae

I am having a problem with brown alge growing on the sandbed and black algae on the rocks, Can anyone give me any ideas how to correct it.. My rock still has some color and purple coraline on them but alot are getting black and dirty looking.. I do water changes monthly ( 10-15% ) on a 75G.. I just upgraded my lights about a month a half ago (720 watts) and that is when everything started.
I tested my water and came back as:
PH---- 8.7
Ammonia----0
Nitrites------0
Nitrates------0
Calcium------450
Alk------- 6.00 meq/l ( I dont know what a good range should be )
Salinity------1.24
Temp-------76 degrees

I'm setting up a skimmer today. How long should I let it run since this is the first time the tank has had one? And also how long should I run a UV sterilizer?

Also what type of cleaning crew would be effective?

 

Water parameters look good about where i run mine at as well.. What is it a light tan to brown dusting covering the rocks and sand ? Or is a slimy longer algae ?

Whats the internal circulation like in the tank ? Also whats the PO4's and silicate levels ? you run a Ferric Oxide reactor for P('s ? Are you adding the food for the diatoms in your make up water ? Might want to test the filters or do you buy water ?
you feeding a lot of frozen meaty foods ?

 

It's more of a brown on the sand, and the rock hace some also but they have the black color now. The circulation is fine or atleast it was now I have to rio 800's but I'm going to change them to a mag drive and pipe 4 comming from bottom in each corner. I dont know what you mean with the PO4's and silicate levels.. No I dont run a ferric oxide reactor what are P('s.. I dont change my filters like I sould I tend to forget about them, I know I need to remember. My top off water is RO and I put roughly 2.5 gallons eveyday or day and a half. I feed every 3rd day and I use Frozen brine ( 2 cubes ) with about 1 teaspoon of Cyclopeez powder. Thats it, other than adding Ca, Iodine, and reef builder when needed... I just got a skimmer today ( coralife super skimmer ) how long do you think I should run it for daily? Thanks for the help.....

 

it could be phosphates, have you tested them? Do you soak your frozen brine before adding it to the tank. It's a good idea to soak the frozen food and then dump that water out. This helps remove the phosphates that are used in preservatives and such. I would run the skimmer 24/7. The only time I shut it off is for it's 4 month cleaning. It sounds like you have diatoms...cerith snails like diatoms. Also I have heard that cyanobacteria comes in not only red but dark green and a blackish colour. Is the black part slimy or bubbly?

 

Oh ya, I forgot, you just got new lights, higher wattage than the previous I would think...did you slowly acclimate your tank to the new lights? It's a good idea to shorten the light period when you get new lights. When I changed over from pc's to t5ho I started out with 5 hrs a day, then slowly added time a week to get to my regular 8hr photo period. Lights, and nutrients cause algae, also lack of flow can help add to the problem.

Is your tank new? Is it a reef, what's in it?

 

No I didnt really acculmate the new lights to the tank. But there were only fish and a couple of corals ( 2 Clowns, 1 yellow tang, 1 blue tang, 1 wrasse, 10 turbo snails, 2 cleaner shrimp, 4 pepperment shimp ), rock , 1 green star polyp the size of a softball and a few mushrooms. Yes I defrost the brine using tank water in a cup until defrosted and then pour in. I'm thinkin the algae problem it related to new lights, cuz like I said it all started after them. And as far a circulation I've tried bigger powerheads but they dig holes in sand and seem to be too strong no matter how and where there placed. So that is why I'm taking the powerheads out and going to use a mag drive and pipe them to the bottom 4 corners.

 

Test for PO'4s aka Phosphates and I'd cut the frozen meat stuff in half and offer them a balanced flake..With no skimmer then you have a build of of dissolved organic matter in the water and add some carbon to the system if you don't already run it 24/7 and as for the skimmer run that 24/7 also. And cut the iodine usage as-well that will feed the hell out of algae..And IMO its totally unneeded.

 

Yes like Tangster said, you need a skimmer, tangs are quite messy and having 2 can quickly buildup the nitrates. When defrosting the frozen food, don't pour the water you soak the food in, into the tank. That water is loaded with phosphates, that why we soak the food and discard the water. Feed frozen infrequently as a treat and switch to flake foods.