Diatoms in an established tank??

[Blazer88]

I just got my 30 gal. tank about five days ago. The tank has apparently been setup for 8 months prior. After the first day or so, we had some slight brown coloring on the sand and didn't think much of it. I added some RO water to top it off and the problem became worse the next day. Then I did a 10% water change and today it was really bad. I've vacuumed some some of it and it removes quite easy, but I'm wondering what exactly it is. I've read about Diatoms but hear those are present in a newly cycled tank. My best guess is that we must have stirred up the sand when transporting the tank that may be causing the problem. It's has ~3" sand bed. Temp is at 77, zero nitrate, nitrite, ammonia, Ph 8.4. I did test my alkalines and they were below 105, but I added some buffer to level that off. Would that cause it? I won't clean it up next time and I'll snap a pic tomorrow moringing if it is present. Thanks for the help guys!

 

[wrightme43]

Not all brown slimey algae are diatoms. It may be a dinoflagellate. If it is, it can kill snails like astera and turbo. It kind of looks stringing and slimey, with sometimes air bubbles in the slime. Kalkwasser drips can help. Carbon may be a solution. If you just moved the tank, no matter how long it was set up, it is unstable now. It will stabilize sooner than a new tank though. Just some thoughts. Steve

 

[Tangee]

I moved a tank recently, just across the room about 6 feet. I was sure there would be no real cycle involved since I used the same water and rocks and there was no real time exposed for any of it. I was totally wrong, I had a terrible diatom outbreak after the first few days that lasted at least 3 weeks. I tried to remain calm which wasn't easy, but with the addition of some new snails and a little patience it all went away without a trace. Good luck, I hope yours does the same!
Susie

 

[mojoreef]

When a reef tank is mature and stable as yours was prior to moving it, the relationship of bacteria/algae to food input is pretty static. As in the amount food is off set to the amount of bacteria that can eat it, so the pendulum is steady and does not swing. In moving it you probibly killed off a bunch of bacteria, some sponges along with a few other things. So now the amount of food that is available is more then the bacteria population can handle, that makes it up for grabs. Algae of a variety of types are johnny on the spot and are using the food to bloom up thier population, thus the pendulum is now swinging to the algael side, once the food is used up the algae wont be able to support itself so it will dies off and the bacteria will bloom up., thus the pendulum swings over to the other side. this pendulum swinging will continue until the tank reaches a point again at some point in time where the populations of both algae and bacteria are static, and thus the pendulum stops swinging. You can combat this or help speed up the process by removing the extra food source at some point in the swing. The easist way would be to remove or syphon out the cyano/diatoms. this will mean that the pendulum swing will be alot slower and it wont take as long to get to the point of static.


Mike

 

[Blazer88]

The problem seems better this morning. On a good note, I haven't had anything die off yet that I can tell. I also put in 20 Nassarius snails the other day and they all seem fine and buried in the sand. I guess I'll just keep cleaning it out until everything levels back off. If the problem does flair up again like it did yesterday, I'll snap a pic and post it. That would probably better identify the problem. Thanks again for everyones comments, I appreciate the help!

 

[Blazer88]

This morning it was fairly cleared up, but within a few hours it turned brown again. I took these pictures to help identify exactly what this is. I also wanted to add that this stuff seems to blanket everything in the tank but nothing under ledges. It can easily be blown away with a turkey baster and doesn't stick at all. Thanks for the help.

 

[mojoreef]

looks like cyano, just harvest it and let it keep doing its job, make it work for ya.


Mike

 

[tankgirl]

Mike, I get a few tiny brown specks on my glass that I think are diatoms, but it's not cyano. What's the deal with diatoms? Are they all bad?

Blazer, hope you don't mind my asking in your thread. It seems like a perfect place to ask, and it's been bothering me for awhile.

The brown specs I've got don't seem to increase. I clean them off when I clean the tank walls, then after a week I've got a few more.

 

[Blazer88]

What do you mean by harvest it and let it keep doing its job? Does that mean I should just leave it be until it goes away on its own? I thought Cyano was a slimy red alge, where as this is brown and very stringy. It also doesn't appear to be attached but rather gently blanketed in the tank. Thanks again.

 

[mojoreef]

Well it could be diatoms, really hard to tell from the distance. Cyano can be many different colors. Regardless if it is diatoms its basically a precusor to algae anyway.
Diatoms are most responsive to silca/silicates, but DOCs (Dissolved Organic Compounds), nitrates, and phosphates are food sources as well. Because he is using ro/di water and has just completed a reset I would imagine its the nutrients and not the silica that is fueling it.

What do you mean by harvest it and let it keep doing its job

Well you have an amount of soluable nutrients in your tank, getting them out of the sand bed or even the water is tough, the cyano or diatoms feed on these soluable nutrients and turn them from soluable to something you can get your hands on. So let them absorb the soluable stuff and then you remove them from the tank in the algal stage. this way you are breaking the cycle, if you dont the algae will begin to die off as the fuel in the bed or water runs out, when that happens you will get a bacterial bloom, it will do the same thing and die off as it runs out of food, this cycle will continue to happen but get smaller as the cycle continues, until it once again reaches the point of being static. Harvesting the algae will mean that all you remove will not eventually starve out and go back in to the bacterial portion of the cycle. Just helps quicken things up.


Mike


Mike

 

[Blazer88]

How do I tell the when it reaches the algal stage so I can remove it? Sorry for all of the questions, but there is a pretty steep learning curve for a saltwater tank.

 

[mojoreef]

When you see the algae growing its in the algael phase, so if its in thier right now, suck it out. You dont have to hit it at its peek. Its all good Blazer no problem

Mike

 

[Blazer88]

Ok, I just used a baster to blow the rocks clean, did a 10% water change, and sucked up the brown off the sand. Looks great....for now. Should I just do this every other day or so as needed untill it stops coming back? Do the lights have any effect on this problem? Thanks again for all of your help as I really don't want to chemically treat the problem, you have been most helpful.

 

[tankgirl]

Hi Blazer,

Notice it goes away at night when the lights are off, then builds back up during the lights on cycle?

My understanding about cyano is that it shows up when something else (bacteria or algae, etc.) dies. It'll go away, once the nutrients that fuel it are gone - and harvesting it outta the tank will make that happen sooner.

 

[oldsalty]

thats not diatoms

 

[Blazer88]

Can you offer any other insight?

 

[tankgirl]

a couple of links for cyano info;
http://www.athiel.com/lib/txtfiles/cya2.html

http://www-cyanosite.bio.purdue.edu/

http://www.reefs.org/library/article/t_crail.html