It's hard in all areas of the sand, but some areas are brown too, like diatoms. I've been adding Kalk to promote coralline algae growth, but I've recently cut it back, and everything seems to be stabilizing.
I have had a cynao problem since the tank move a month ago. I am doing a 5 gl. wc every couple of days. I missed a few days and today it was starting to grow on the rocks. I waited to do a wc till tonite thinking that the longer the lights are on the worse it gets. The only problem with syphoning cynao out is I take too much sand along with it no matter how careful I am. I would imagine I get quite a few pods that way to. I did rescue a ceirth from the bottom of the bucket.
The lfs gave me what I believe is maracyn. He says just throw it in and keep an eye on the skimmer. He says I probably only have to do this once. I have never added any chemicals to my tank and am very hesitant. But I can't keep lugging change water up 10 steps to my apartment every couple of days. I could have one of my grandkids do it for me but that means taking them out dinner and a 10 mile ride back to their house. Would be pretty expensive water changes after awhile.lol.
I am in the process of ordering metal halides lights for the tank. Will that make the cyano worse?
I haven't added the maracyn yet. I don't dare. Do I turn off the skimmer when I add it or leave it on? Do I do a wc after a certain amount of time? I just handpicked a bunch of cyano off my rocks and sand. It's getting worse. I hope somebody is on the board that can help me tonight. TIA
Maracyn can throw your Ph and kill some of your bio so be carefull!!
About the hard sand..................
My fish guy said my hard sand is just from calcium. He said to just take my long handle algea scaper and poke it around to soften before my water changes. I got a sand sifter star and horseshoe crab and it seems it all went away. Same with my brown algea. Since I moved the water here is way high in nutrients and I couldn't believe the difference in algea. I got a RO and everything has calmed down now.
I had the same problem with my tank and it all started when my Prizm skimmer decided to not skim. I didn't realize how much the Prizm didn't work until I got a good skimmer. I now have a CPR bakpak skimmer and it's amazing. Only about $130 from any site online (easiest to do a google search for the name and price them out) and I really love it. My problem hasn't gone away completely, but I'm doing water changes much less often. A lot of people love Prizms, but I've never had any luck with them. It won't completely eliminate your problem, but I really would try a different skimmer. It makes a world of a difference and you won't be wasting a ton of hard work to have the water turn junky in a few days.