I'm new to having a salt water tank. Its a 28 gallon, nano-cube HQI. Has a Eshopps 75 hang on skimmer that I just added. My temp ranges from 78 to 84, so I just purchase a chiller, but not set up yet. The tank has been going for about 6 months now. I use RO water, my nitrates and nitrites are zero. Change 15% water every week. Saline is 1.023 to 1.024, Ph and alkalinity is in ideal range. I have 3 inch sand bed. I have a BTA, 1 Mandarin and a couple of fire shrimp. I had a couple of clown fish, but they didn't survive past 2 months. I also have a few soft corals that are alive but not doing great. I also have 20 or so of Nassarius snails, that are reproducing. I don't want to add anything else till I get everything going correctly.

My problem is that I have a crust that forms on the top layer of the sand bed its almost like an algae, but not sure. Its reddish rust color. I need to break it up and clan it out weekly.

Does anyone have any ideas? I'm getting quite frustrated.... any help would be greatly appreciated.

Sounds like cyanobacteria to me.

General remedies are increased flow over the affected area, removal of nutrients feeding it(nitrates, phosphates, etc etc) and make sure that you're not feeding too much, or if you're feeding frozen food, don't let the liquid that you get when you defrost it reach the tank.

Welcome
Can you provide a picture?

Is it crusty or slimy? Crusty would indicate diatoms, slimy would indicate cyano.

I'm only feeding once a day and very little, but the frozen I am using does produce an olily mix when I thraw it out, so I will work on that. I have the original two pumps, but will upgrade, should I plan to add another in the tank itself? if so which one?

Thank you>



Thanks.. I just cleaned it out today, but next time I'll see if I can get a picture.



You know I think its slimy, not hard at all. I forgot to mention I have an orange sponge and it gts covered with it too, its the reddish rust color and slimy.

Any other thoughts would be greatly appreciated... Thank you...

Its Diatoms. Thaw out that frozen food in rodi water then I use a piece of cheese cloth to strain mine and get all the juice out. Not rinsing and straining frozen food will give you some sandbed problems fast.

Thanks, sounds like that could be my problem..

What you are experiencing is somewhat par for the course- it does take time for everything to balance itself out. Just keep up with regular water changes and after awhile (it may take a few months) things do get better.

Ditch the skimmer- you don't have the kind of bioload or coral inhabitants to make it necessary. Softies need some nutrients in the water to thrive. Reduce your frozen feedings- once a day is way too often. I would return the mandarin if it were me- you need a larger, more established tank with a steady supply of live copepods to prevent it from eventually starving.

I would add a variety of snails, not just nassarius- nass snails are carnivores/detrivores, not really algae consumers.

You can also stir up the sandbed and vacuum the cyano. It doesn't solve the problem but it makes the tank look better and prevents it from building up on your corals.