Brown algae

[Maurice2]

Lost all 11 fish to ich a month back. After watching 5 die from suffocation I put the rest out of their misery when they showed signs of suffering. An unpleasant experience, but from which I learned a lot.

Lesson: LFS may be nice and knowledgeable but they are primarily there to sell fish; thus they have little interest in your fish surviving for long periods.

Tank is fallow since (except two survivors, a bluefoot hermit and a starfish) and I don't plan on introducing anything until well after Easter (that'll be about 7 weeks).

Last Saturday I removed and boiled the sand, did 100% water change and added 20Kg of live rock (40Kg now in total). Result looks like this (tank is 3 months old):

6 days later I'm seeing this brown algae growing again:

I'm not feeding or putting anything in the tank. The chemistry is all at 0.0, 1.021, 25°C, PH 8.1. 480L, wet-dry sump, 600L/hour Eheim mechanical filter, 1100l/hour powerhead behind the ceramic decor, 2X50W 15000K lights.

Something tells me that I need to get rid of this stuff before even considering adding any livestock. Is there a kind soul who could give me some guidance please?

Thanks in advance

 

[TheRealFF]

Is that LS that u boiled? Why did u do that for?

The algae is probly diatom which shows that ur tank is fully cycled, and will eventually die off. Can we get more info about ur tank set up?

 

[pkremer]

I too am curious about the purpose of boiling the sand...did someone recommend this to you?

I agree that the algae is most likely a diatom algae. However, this is a sign that your tank is beginning a cycle, not necessarily that it is fully cycled. Good idea to leave the tank fallow for the next 7 weeks, any ich that was in the original rock should have died by then.

As far as the diatoms, no need to worry...this algae will burn itself out over the next few days/weeks. It's not pretty, but everyone gets it at the beginning of their cycle. I'd be very surprised if it wasn't all gone in the next few weeks. You said "again" like you had seen it before? Is it the same kind that appeared at the beginning of your last cycle?

Paul

 

[Maurice2]

Boiling the sand just struck me as a chemical-free way of cleaning it. In addition there was a certain moral satisfaction in thinking that maybe a few remaining Cryptocaryon met with their maker

I setup the tank mid-January and cycled it before adding livestock. I've had this diatom since the beginning, it never seems to 'burn itself out', it just gets replaced (covered?) by green plant-like algae.

Observing closely, it grows the most where there is good circulation and plenty of light and only on synthetic surfaces (there is practically none on the LR).

What I'm curious about is what this stuff is living off? (and living vigourously, too) If nothing enters the tank, at some point there will be no nutrients left and growth must stop, no?