[Dimik]

Hi, I've started my first saltwater reef tank. It's a 29g tank, cycled (no rock yet), just a few inverts there (hermits, 2 shrimp, snails, urchin) and I noticed some small strands growing out of the sand. It's a strand with what looks like a bud on top.

This is weird because I have no rock in the tank and everything else I've used was either new or sterilized with vinegar-water mix and left to dry a few days.

Is this just some type of macro-algae? It's growing on the side of my tank closest to the window and I do have some brown algae growing on the glass nearest to it.

 

[weimers75]

Not sure about the tube...BUT I noticed a few issues

1: Your tank isn't big enough to support an urchin, especially since its so new. You have no algae in there for it to eat, and even if you did it'd clear out a 29 gallon in days
2: Your tank isn't cycled until you add live rock and depending on how bad it is you could lose your other inhabitants. The main premise behind cycling is getting the bacteria in the live rock in high enough numbers to handle the bioload. If everything was new and/or sterilized then you have nothing to kick start the cycle
3. The brown algae sounds like diatoms and is pretty typical of a new tank

 

[Dimik]

Not sure about the tube...BUT I noticed a few issues

1: Your tank isn't big enough to support an urchin, especially since its so new. You have no algae in there for it to eat, and even if you did it'd clear out a 29 gallon in days

I did my research before picking this specific urchin. It's a small Shortspine Urchin, grows to 3 inches, minimum tank size of 20g and I actually had plenty of algae (green spot, diatoms so far) growing on the glass because I intentionally placed it in a very high light location (large window). I recently moved the tank to a more stable/permanent location now that it's cycled and wiped most of the algae off the glass, leaving some for it to eat. Also, I'm direct feeding it nori sheets every 2 days.

And also, as this is my first tank, it's a bit of an experiment to see how much I like saltwater. I'll be moving and upgrading the tank to something bigger (at least 75g) early next year so I doubt he's going to outgrow the tank in a year.

I don't mean to blow you off, but it was not an impulse buy.

2: Your tank isn't cycled until you add live rock and depending on how bad it is you could lose your other inhabitants. The main premise behind cycling is getting the bacteria in the live rock in high enough numbers to handle the bioload. If everything was new and/or sterilized then you have nothing to kick start the cycle

I used the bacteria in a bottle to start my cycle. I have a filter rated for 75g with two large filter pads plus a 2 inch sandbed and some basic ornaments. There should be plenty of surface area for the bacteria to live in. AFAIK, you don't NEED to use live/dry rock to cycle, it's just a convenient way to kickstart your tank is my understanding. I cycled in 40 days, now ammonia and nitrites are zero.

In any case, I'm adding dry rock next week once I'm finished building my sump.

3. The brown algae sounds like diatoms and is pretty typical of a new tank

Interesting, I did not know diatoms could make structures. The diatoms should go away soon once I have my sump running. I got a LOT of free chaeto.

 

[weimers75]

The stick coming out of the sand isn't diatoms...I was talking about the brown algae on the glass. Your urchin won't eat the diatoms...diatoms like high nutrients and low water movement. So the sump will help, as will increased water movement.

I also wasn't implying you HAD to cycle with live rock, but your tank will likely cycle again when you add your dry rock - there will be lots of dead material on it that will decay...the rock (whether dead or live when its added) provides much more surface area for the bacteria for the nitrogen cycle than plastic ornaments and sand. In addition, in tanks that small you'll notice the fluctuations more. The bigger the tank the less you'll notice the fluctuations. You'll actually notice if your nitrates go up bc your urchin will lose his spines.

 

[Dimik]

The stick coming out of the sand isn't diatoms...I was talking about the brown algae on the glass. Your urchin won't eat the diatoms...diatoms like high nutrients and low water movement. So the sump will help, as will increased water movement.

Yep, I noticed he hasn't been touching the diatoms and not sure about the green spot algae. He seems to be doing fine so far, not losing spines. I'll be adding a powerhead in a week or so.

My main concern with the stuff growing out of the sand is that it's not dinoflagellates. I've heard that's one of the worst algaes to get and toxifies the water.

I also wasn't implying you HAD to cycle with live rock, but your tank will likely cycle again when you add your dry rock - there will be lots of dead material on it that will decay...the rock (whether dead or live when its added) provides much more surface area for the bacteria for the nitrogen cycle than plastic ornaments and sand. In addition, in tanks that small you'll notice the fluctuations more. The bigger the tank the less you'll notice the fluctuations. You'll actually notice if your nitrates go up bc your urchin will lose his spines.

Got it. I was planning on testing the water daily after introducing the rock out of curiosity to see if it would create a mini-cycle anyways. The rock is bone dry, I don't think there's any organic material that'll be decomposing.

 

[weimers75]

Even bone dry it will have dead matter on it

 

[Zericorals]

I would get that fake stuff out and get some dry rock then add bacteria so it can seed it.