Help identifying algae, I think.

[BDeVaney]

Hello, I have a 20 gallon tank 2 weeks old. I put live rock in it on day one and I have added a little more over the past 2 weeks. Also 2 small fish, some hermit crabs, and a few small mushrooms that came with some of the live rock. I know things were obviously starting to grow on the rocks which is supposed to be normal and good. However, today I noticed quite an increase in what looks like brown algae or something brown at least. Here are some pictures, I'm hoping someone can help me identify this stuff and figure out how to manage it. Thanks!

. Those last 2 pictures show the brown junk on the glass.

 

[Trex]

Appears to be diatoms. Fairly common in a newly set up tank. Time and keeping your parameters (( water changes with RO/DI { 0 TDS } water )) in check should help.

At this juncture I wouldn't be too concerned.

 

[BDeVaney]

Ok thank u that was quite a relieving message. I have planned on changing 20-25% of the water tomorrow with saltwater the LFS gets from a nearby marine institute. Sound like the right thing to do or no?

 

[BDeVaney]

Also what is "0 TDS"?

 

[Trex]

T == Total
D == Disolved
S == Solids.

To be quick (( fuller answer in the AM )) --- basically gives you an idea of how well your RO/DI membranes/resins are functioning. The lower the number the better, with 0 being ideal.

The only issue with the water that you are using it is COULD (( not saying that it would )) be full of nutrients and cause algae breaks --- given where it is coming from, I wouldn't be too worried, but just keep it in mind down the road if you have some unexplained outbreaks. Can't really use an TDS meter on water that has salt, will get a high reading from it "seeing" all the dissolve "salt" solids.

 

[BDeVaney]

So the goal is to have 0 TDS in the water pre salt?

 

[Trex]

Yes.

Part of the issues is that it is difficult, at best, to determine what would make up any TDS over 0. A reading of 10 could be some harmless salt, or it could be very harmful copper.

 

[BDeVaney]

Ok well I bought the saltwater from the LFS today. There were a lot of people in there buying it so I figure it's ok. I also bought 5 turbo snails and a magnetic algae scrub for the glass. One of the issues still remaining is that there has been a little bit of build up of stuff on the bottom of the tank. I imagine most of it is die off from the rocks, food, and fish poop. I have one of those basic siphons that I can use for cleaning the sand but it's not good enough to get that stuff off the bottom. I'm concerned that the stuff my have a lot of nitrates. Should I just use my net and scoop that stuff up or can it be left there?