Brown dots everywhere

The_Skrimp · Jun 21, 2020

My tank has brown chicken pox!
I’m about five weeks into my cycle and things are moving super slow for me. But now I have brownish fuzzy spots everywhere. The thing is... I don’t know if their diatoms or not because my cycle has hardly started yet.
I have
Ammonia .5ppm
Nitrite 0
Nitrate 0
Phosphate 0

And I thought diatoms needed phosphate and nitrate to pick up before they appear. Could this be something else?

T-J · Jun 22, 2020

At 5 weeks you should be basically out of your cycle. What are you using to cycle your tank? And what test kits are you using?

The_Skrimp · Jun 22, 2020

I'm using the API test kits. It's a fifty gallon tank with a medium sized sump so nothing too big. I can't figure out what I'm doing wrong. I started with live sand, dry base rock, and a bottle of Dr Tim's nitrifying bacteria. I also added a couple pounds of live rock to the tank just a couple of weeks ago to see if it would help speed things up. At this point, I've completely dissolved a shrimp in the tank. After that my ammonia bumped up to about 0.25 so I continued to ghost feed my tank every day for the rest of the time. I've been feeding pellets, flake, and occasionally frozen foods. There's definitely a lot of organic material in the tank and my skimmer has producing skimmate but my ammonia hit about 0.5 just recently (I'm almost at week six now). I never saw any nitrites or nitrates and I'm testing just about every other day. They keep reading zero. About two days ago, I started noticing these brown fuzzy spots appearing everywhere. It's not a dusting of brown like diatoms. I had a diatom bloom a couple weeks ago so I'm thinking this is something else. It's round brown spots... Considering that I don't have any nitrates or phosphates yet, I was worried that it was cyno or dinos due to all the organic material in the tank and because I was running my lights. This morning I decided to do a ten percent water change (first water change since I started the cycle) and syphoned as much of it as I could off of the substrate and the rocks. They came up pretty easy.

As of right now, I've turned off the lights and shut the blinds near the tank to keep it in the dark till this goes away. The problem is, right after the water change, I did another test and my test kit is not reading any amonia now so I probably just reset my cycle. I'm wondering if I should just start over and add another shrimp to the tank or if this time I should just add several shrimp.

T-J · Jun 22, 2020

When ghost feeding, you don't need a lot of organic material for that cycle to occur. With you adding bacteria, I'm guessing you cycled, but since you kept feeding, you perhaps are putting more matter in than you bacteria can handle at this point.
You have ammonia, so there is food in the tank for the bacteria. When you see nitrites, you know you're almost there, then Nitrates. When you see Nitrates, your Ammonia and Nitrites should be zero. Also, API kits are crap, especially for low levels.

skydirt · Jun 22, 2020

i'm getting the same thing in a tank that's been up for six months. I have 5 fish and a few corals and all are healthy. I'm not sure what the spots are either.