PDA

View Full Version : Algal cycle after tank crash / cycle


travis32
11/29/2010, 06:46 PM
O.k. well, 5 -6 weeks ago, I crashed my 55g tank with a mixed limewater OD. (I threw a powerhead in the top off kalkwater.--- thinking this was a good idea..)

Killed everything except my fish which I rescued before it killed the fish.

Ammonia was at 8.0 as the millions of asterina starfish died and the gabillions of flatworms died...

Some things survived, like a few hermit crabs and a few snails... not sure how, but they did.

At 4 weeks, the ammonia had gone from 8 to undetectable. I didn't feed anything during those 4 weeks, just let the tank crash. I moved some of the rock, cleaned it in salt water and moved it to a heated rubbermade tub of fresh saltwater and let around 70% of the rock cycle in the tub. Which is now in my new 125g tank and is cycling again, although a much smaller cycle.

So, back to my 55g. I placed all the corals I got for the 125g (previous owner sold me the corals and tank / stand, etc..) after 5 weeks of a very heavy cycle.

The corals are doing great in my 55. However, the tank is going through some strange strange cycles... I changed about 50% of the water during that big cycle with 0 tds RODI water. I had been using 70 TDS RO filtered water up to that point.

Fast forward about 1 week or 2 weeks after the cycle finished. 1 week after placing large corals in the tank. I am having the largest Cyano outbreak I've ever seen. I'm not feeding the tank more than once a week just to feed the corals and keep it cycled.

The thing is the cyano is not damaging the rock or the corals. It's attached itself to all 3 sides of my tank glass. The front I scrape once a week, but there's been very little cyano on the front glass. The sides and the back are covered in cyano. I mean, You can't see through the glass, it's a solid carpet of cyano.

I'm debating leaving it, because, my understanding is that cyano and algae in general absorb a few things -- Phosphates and/or other nutrients that cause algae in the first place. If the rock is leaching phosphates, having the cyano to absorb it and keep the corals from being damaged is a good thing isn't it?

Provided it doesn't grow onto the rock and corals.

I know it looks ugly, but once my 125 is fully cycled, I'm planning on relocating the rock and corals to the 125g at the same time, then tearing down the 55 anyways. Then I'm going to dump the sand into buckets and probably try to sell the sump, overflow, and sand.

Anyways, just wondering if this much cyano after a really heavy cycle is normal or if this is normal for rock that's leaching a lot of bad stuff?

Metal Man 1221
11/30/2010, 03:01 AM
I would assume it to be both, if the ammonia spiked quite high during the crash cycle i would assume that a lot of the rock has internal die off so you still have a lot of nitrates and phosphates being leached from the rock even after the water had its cycle the rock may not be done "re-curing". i would say take it slow until you notice growth cycles begin to happen less frequently, and eventually stop. at this point you should be fine. As far as letting cyano grow out, as long as your not seeing any compromise in the corals health you should be ok with it. however if it is growing quite rapidly i would suggest vacuuming the cyano every three to four days, depending on how rapidly the cyano grows thick.

travis32
11/30/2010, 07:34 AM
Thanks Metal Man. Yeah, it's fairly thick on the glas. I used a turkey baster to get anything off of a coral if I see any growth.

I noticed some of my "recuring" rock that don't have any corals on them are covered in cyano. So, I need to vacum those off so they can continue the curing process.. I'm hoping the 125g finishes it's cycle soon. So, I can relocate the corals to the 125g and just tear down the 55g alltogether.