Alge & Water Changes...

I everyone. my husband set up a 150 gallon SW Tank almost a year ago now. I do all the water test's and they always come back perfect, We never had a fish die (yet) not even the starter fish that we recently caught & took back to the store. We are now getting a lavender-purple-ish alge on top of the sand and I think on the rocks. We have no live rock, but have a anemone that the Chocolate Clown fish just adopted (finally) Should we do a water change? We have never done one before. also does it make a difference if the lights sit on top of the glass of the tank? Thanks, silverbells from Michigan







here's just a couple of pic's. I'm not really sure how to post them yet...Help!!! But you can see the alge in some places. We also have 3 small Clown Fish, Choco. Clown, Spotted Grunt "Spot" Fox Face, Blue & Yellow Angel I call "Michigan", Korean Angel that's mean, and I've heard he'll grow to 12"! He's the blue & White Swirl one, 2 blood Shrimp, Scooter Wrass, Poly Jaw, and some snails. Does anyone know about the Korean Angel, I think i want to remove him. I just want everyone to get along. Also concerned about purple alge

 

It might be cyanobacteria, or some call it red slime algae. Do a google image search for those terms and see if they match what it looks like. Here's a link about it Red Slime Algae (Cyanobacteria)

 

And about the water changes, if you don't do them (and some don't) you should be checking for and dosing elements like calcium, iodine, etc. These among others can be depleted and not replenished since you aren't doing water changes (where they would come from adding new salt). You might want to consider doing water changes at least once every couple months or something...

After looking at your seabe anemone it looks a little white (bleached), your goal with him is to make it a nice brown color. I'd start feeding it small pieces of meaty food 2x a week or so until it can build up it's zooanthelle and get healthy.

 

that sweetlips is going to be waaaaaaaaay too big for your tank in no time flat.

 

thanx for your quick response! Sad news..."Spot died, it's our first loss and of course he was my favorite We only had him fro a short time but he reminded me of a little dumb happy puppy.) Could he have been stung by the Anemone? I was so sad I had my husband take the Koran Angel and the Maroon Clown back to the store because of aggressive issues. The Maroon Clown chased the Percula Clowns all the time & bit them, come to find out your not supposed to mix "Clown Fish" why don't they tell you this stuff at the LFS, we told him what we had in the tank...and the Koran Angel shouldn't have been agressive (so they said) but he was mean. So I'm hoping to have a peaceful tank once more.
We vacuumed up the purple alge and the water change is looking good so far, how soon should I test the water after the change? And now I know how easy it is to do the water change, how often should we do it?

 

Simply Directing more water flows to the areas with the cyano problems and it will kill it off. The tetracycline you dosed will also kill the bacterium off but its a indicator of low dissolved oxygen levels in the system .And the red slim killer is just hiding the effects and not curing the cause of the bacterium.