Diatoms / Shallow sand bed maintenance

[lastlight]

I have a diatom outbreak I think. Layer of this brown/orange algae and tons of bubbles bleeding from my sandbed. I may have made things worse by stirring this algae up to release the bubbles I'm not sure. Been doing this for a few days and now I'm not sure that's a good idea. I've heard stirring a shallow sand bed is good. Some people say don't disturb but I think that pertains to DSBs? After I stir up the sand the layer returns and the bubbles are produced again within hours if the lights are on.

What's up with this and what's the best way to manage/deal with it? I've heard these are part of new setups...never had this with my first tank.

And where would the diatoms come from? Won't a membrane remove diatoms from our tap water? I've stopped stirring my sand for now. Also I notice the bubble production seems to be photosynthetic...well it really gets going when the lights have been on a while. But they come from INSIDE my sand.

Any ideas? And is this issue also linked to phosphates/nitrates and not just diatoms?

[bignose]

I had a similar problem in my last tank. I just sucked up the bad areas and over time it went away. My tank was around 5 months old when it happened and it took a couple of months to clear up.

[lastlight]

Do you mean you sucked up the film of algae or the actual sand in that area as well?

I'm also wondering with a shallow sand bed if it's ok to vacuum the sand (siphon tube inserted until you touch glass and just suck debris out) like one would do with gravel in a FW setup.

[kien]

Sounds normal. I've had diatoms with every tank that I've set up.

I usually just let it be. It dies off eventually. It is unsightly and I suppose you could stirr your shallow sand bed (I used to do that but didn't really help). Again, it will typically go away on it's own as your tank matures.

[lastlight]

Thanks guys.

So it is ok to stir/vacuum the sandbed if I do want to?

It's still a useless exercise as all the fish poo etc is heavier than much of the finer sand particles. Friggin' sand.

[zum14]

Tagging along. Im having the same problem. I was kind of putting it towards nutrient problem (I still have a bit of a phosphate issue, working on it) but interested in hearing the opinions.

[fishytime]

Diatoms are usually caused by one of three things........excess nutrients, either from over feeding or from die-off from a new tank cycle........old bulbs can sometimes cause an "outbreak" as the color temperature drops with bulb usage.....or it could lack of flow, diatoms tend to take hold in areas of low flow.........all relatively easy fixes..... or you could pick up some "coral snow" to treat the symptoms....

[soapy]

As I understand it Diatoms require a combination of excess nutrients and silica to thrive. Once they burn through the silica in your tank they will wane. Of course then if you still have a lot of waste in the system you will start to see cyanobacteria or algae.

[lastlight]

Until a few days ago I was using the stock bulb still so that may have contributed. It was the floor model Solana from Big Als so who knows how long that bulb ran but surely over a year unless they'd change it (doubtful).

When I got my two fish I was overfeeding a touch to ensure they got enough which may have been silly but I wanted to be sure. I'm feeding much less now.

I modded my 6025 and should be getting about 1100 gph which I think is decent. About 30x right now. It seems ANY sand that gets light is affected. The sand under my cave is bone white. so I think flow is less of an issue.

So those are likely culprits. How does the silicate generally leave a new system? Mainly through manual removal or skimming?

Thanks

[soapy]

Originally Posted by lastlight

So those are likely culprits. How does the silicate generally leave a new system? Mainly through manual removal or skimming?

You know I never really thought about it. I suspect the silicates get tied up in the skeletal structure of the diatom, but what happens to them after that I don't know.