Brown algae


Reefing newb
Hi, recently me and my wife set up a new saltwater tank. Having read dozens of conflicting sources, I may or may not have made bad choices in setting up the tank. In any case, here goes:

We have a 16gallon tank, with with I filled up with tap water (and used the water cleaning stuff that came with the tank), and have crushed coral (cleaned w/ water) as the substrate (I wanted sand, wife listened to LFS advice and overruled) as well as in the filter. We have about 2.5 lbs of live rock.

Before even putting fish in the tank we had this brown looking algae grow on the substrate as well as the live rock. After consulting with the LFS they said it would go away but we could put a cheaper fish in as well as a cleanup crew. In goes a damselfish, 5 snails, and 3 tiger conchs. They did great for about two days and then slowed down the cleaning greatly.

Couple weeks later we add a clownfish and a camel shrimp. The fish themselves seem uncomfortable in the tank, sticking to one side opposite the current. After adding the clownfish the conchs died one by one, which the LFS stated was at the hands of the fish. At this point I decided to get a test kit, (bc after all, the LFS insisted we didn't need one *until* we started noticing stuff), and found NO3 to be high. Do not know whether this is due to the conchs having died or other reasons.

Sorry for the wall of text, I hoped it would be better to be thorough.


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My first piece of advice is don't listen to your LFS. There are some good ones out there but it doesn't appear yours is in that select few. It was a good move buying your own test kit regardless of what your LFS said.
Second piece of advice is go slow. Patience is your friend in this hobby. You have diatoms ( the brown stuff) and they are perfectly natural in a new tank. They will die off when they deplete their food source which is silicates.
Crushes coral is tough to keep clean of detritus and food waste so you will need to be diligent in your water changes and tank maintenance. Sand is the better option.
The conch could of died from the nitrates or lack of food. I highly doubt the fish would be the culprit.
Third piece of advice is ask questions here and do your own research that way you have the piece of mind of knowing exactly what you are putting into or doing to your tank. The LFS is there to make money off of you and we simply want you to enjoy your tank and help you keep your livestock thriving.
Tap water is tricky with saltwater systems. It is better to use RO/DI or at least RO water. Some people use tap water successfully but just keep in mind it can cause you problems.

I hope some of this helps and agains welcome to the hobby!
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Thank you very much for the reply! I'll keep siphoning the bottom regularly, but I'm going to try to switch to sand at some point. Once I switch to sand are the snails still going to be as effective, or should I think about another cleaner?