Q&A with Keith, 3/27/09
About 2 months ago I was having issues with my Red Sea Max. I was getting a lot of red slime on my sand. I went to my LFS and he said taking the sand out and running the system with no sand would be the best thing to do. Since then I have had nothing but problems. Does live sand "go bad?" What do you recommend?
Red slime (cyanobacteria) can occur in aquariums with or without live sand, so I do not think that was the route of the problem.
Red slime commonly occurs in tanks that lack adequate water flow (many Red Sea Max and nano tank owners add an extra powerhead to thwart this problem), have high nutrient levels (phosphates and nitrates in particular) or have old bulbs and the color spectrum has shifted (learn how often to replace your bulbs here). It may be any one of these issues causing your problem or even a combination of some or all of them.
So what can you do to stop cyanobacteria from taking over your tank?
First, address the aforementioned problems and that should make a big difference. Remember to increase water flow, do not overfeed, perform regular water changes every 1-4 weeks using a high-quality salt mix with filtered water (preferably RO or RO/DI) and remember to change your bulbs at appropriate (regular) intervals.
During your water changes, try to siphon out as much of the red slime as possible. Some hobbyists will turn off their lights for a few days to slow the growth of the slime while working to rid their tank of it.
There are also medications that kill red slime, but in my humble opinion, these should only used as a last resort. If the underlying issues causing the red slime are not addressed, red slime medications will likely only fix the problem temporarily.
To address your "does live sand go bad?" question: this answer is a bit complicated. If you were to leave the sand stagnate in a bucket of saltwater, then yes, it would indeed go bad.
Live sand needs water movement to help it stay "alive." The critters living in the sand need the oxygen in moving water to stay alive. The sand itself doesn't need to be moving, only the water flowing around the tank to help with gas exchange.
Now, the more complicated part: the critters in your live sand may change or deplete over the months and years your tank is in operation. This may be due to lack of food, predation by other organisms, siphoning or other circumstances.
Many experienced hobbyists recommend adding a little live sand every so often (up to a few times each year) to help keep a diverse population within the sand bed. Some aquarium clubs even hold "sand swaps," where members bring in a Ziploc bag full of sand, mix them all together in a bucket and then everyone goes home with a "new" bag of live sand to add to their aquarium. You may even be able to find a LFS that sells a live sand "booster kit" that will contain more organisms for your sand.
Hopefully this has helped answer some of your questions. If there is anything more we can do to assist you, please let us know.
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