Can someone ID this? Updated!!!!

In the picture, it is the brown stuff that I am trying to ID. It just started in my tank around last Wednesday. It was about 4 days after adding 20 pounds of live rock and two 24" T5 lights (1 actinic, 1 10,000K). I was using just regular tap water for everything until I read about all the negative side affects of doing this. I now use RO/DI water for top offs and water changes.

PH: 8.2
Ammonia: >0.25 ppm
Nitrite: 0 ppm
Alk: Normal (between 1.7 - 2.8 Milli equivalents per liter)
SG: 1.025

I didn't test for nitrates and I can't test for anything else right now.

I just added the power head today for increased water flow. The picture with the red mushrooms in it is what my sand bed used to look like. This brown stuff is growing only on the sand and the rock that doesn't have coralline algae on it.

 

That looks like typical diatoms to me

the tank is relatively new I assume?

they normally occur for me between weeks 2 (fastest I ever got them) and week 8 ( the longest I noted before they arrived)

typically, they get worse before they get better and then they dissapear completely
they use silicates to construct their skeletons, and once the silicate is all used up, they die off

this can typically take between 2 (mild cases) and 6 weeks (severe cases), depending on the amount of silicate in the system
with having used tap water, my opinion is, you might have a more severe case and this brown could be around of up to 6 weeks

no action required on your part - they are naturally occuring in majority of reef tanks
silicates can be found in new plastics etc, so even those that use RODI to set up tanks
will experience them, but possibly milder cases

Steve

 

yup I got them in my tank now.Ive used RODI water from the start (2 yrs) but I added new sand last month.They will go away by themselves.

 

+2

Definitely a diatom bloom. Since you started with tap (I made the same mistake, mind u) I'm betting that once the diatoms have used up all the sillicates the next thing, or even while diatoms are still present you will have some Green Hair Algae or GHA as we like to abbreviate it here.

Like Steve mentioned, nothing u can do with the diatoms. You can manually remove them and siphon them out, but they'll keep coming back until all the sillicates are used.
For the GHA, if and when it comes, there are other strategies to keep it in check, including light feeding, shorter lighting schedule, running a GFO reactor, etc.

Just keep doing water changes with good ro or ro/di water. It may be a good idea to buy a unit and make your own water. It will pay by itself in no time, if u compare the cost of fresh or salt water at your LFS.

Sent from my phone using my two opposable digits

 

I ran out of ro water and was bound and determined not to wait so I did a half gallon water change with treated tap water. This kicked off a second diatom bloom in my tank that lasted about 2 weeks. I sure won't make that mistake again. Lol

 

so my father was using tap water for years i just over hauled his tank with ro water for fathers day cleaned it all up for him now today he got the same brown film on the sand and his rocks so im thinking this is what it might be

 

With that being the case, it will take a while for all the silicates to leach back out of the rock and sand. The best thing is leave the diatoms alone. As mentioned earlier, they'll use up the silicates and then die off on their own.

 

I appreciate all of the great advice. My tank has steadily been getting more brown, but I'm not worried about knowing that the problem will take care of itself within time.

 

Is this bubble algae? I just noticed this a few hours ago. How do I properly take care of it?

 

Carefully pull them out. One by one. Don't pop them. It is a good idea to do it in a bowl with some salt water and have enough water in another container to rinse them out very well after removing all of them.

Sent from my phone using my two opposable digits