Re-Use old live rock

[PhilDib]

I had an 18 gal reef tank running for 2+ years. It eventually died because of excessive hair / red algae. I have left the tank untouched for 6 months until I decided what to do with it. No lights no filter. I recently turned the lights on and noticed lots of star fish all over the glass, little critters running on the bottom. The water seems crystal clear and the rocks still have Coraline algae over them. There are maybe 2 rocks that still have red slime (only a tiny bit though). I am going to be setting up a 26 bow front and I was wondering how to find out if my live rock is still good. If I had problems with red slime in my old tank will this transfer over?

[tinyreef]

should be fine imo. as long as you didn't nuke it or treat it with anything weird, from the amount of inverts it sounds ok tho.

 

just clean off the excess debris and algae to make you life easier later on. try to use the tank's own water versus FW or another batch of ASW. in fact, if there's a lot (i.e. livestock, coralline, etc.) on the 'old' LR that you want to save then you may even want to acclimate it like livestock.

 

slime can result from poor water dynamics and/or excess nutrients. there may have been something dead or your input was more than the system could process/bio-lock or your output was zero (e.g. no wc's, skimming, etc.). hth

[Aiptasia]

"Good" is a relative term. Chances are, there's been quite a lot of die off in the LR but it probably still contains some life, unless it's been allowed to completely dry out.

 

You'll need to set it all back up and cycle the tank out again. Dead LR has a tendency to host problematic algaes first and will probably overgrow again with diatoms and green algae if you run full spectrum light over the tank. I would suggest running nothing but actinic 03 light over the tank to encourage the heavy re-growth of corraline algae, keeping the pH stable at 8.3 and making sure you have 400-450 ppm calcium in the water.

 

Corraline algaes are a lot more colorful and grow better at deeper depths where there's only blue light available to them. They really love actinic light, so i'd run the tank for the entire cycling period with nothing but actinic light. Yes, the tank will look like it's been dyed with ty-d-bowl, but as long as you suppliment with calcium daily and keep the tank's pH and alkalinity (7-12 dKH) stable, corraline algae will grow instead of green hair algae and diatoms.

 

Go ahead and add a janitor crew to the tank as well. Add snails at a 1:1 ratio of snail to gallons of water and add 1 hermit crab per two gallons (red legged, blue legged, etc.). Getting them in there right away will help keep problem algaes under control and create a nitrogen source for the beneficial bacteria to feed upon.

 

After the tank cycles, you can start gradually introducing full spectrum light to the tank. I'd advise limiting the full spectrum light to 2 hours (eight hours actinic) for a week, then the next week upping it to 3 hours (seven hours actinic) and then gradually upping it again until you get to 5:5. Then, you can begin running the two spectrums of light in combination (50% full daylight, 50% blue actinic) for a full 10 hour photoperiod. You can add deep water corals to the tank after the cycle, or if you'd prefer mid to top water corals, wait on adding them until you can get the lights running at full strength.

 

This is a slow, safe, gradual approach to encouraging corraline algae growth and limiting problem algaes. I'm sure others here will have differences of opinion, but what you're trying to do is similar to setting up a tank with arago-crete and growing your own LR, which I have done with success following this method. If your reef janitors can't control the cyanobacteria, you can add a reef safe product like ny-cyano or erace to kill it off.

[PhilDib]

I did use one of those anti-red slime medications at one point. I was trying so hard not too loose everything. Is that a bad thing? Could I still use the rock in a different tank?

[hoobla65]

yeah, id say the rock is fine, even if most of it died, the live part will re-spread to the dead part in time. I'd also consider a decent cleanup crew for your new tank, that alone would make a TON of differance in the algea groth.

[TiGs]

Originally posted by PhilDib

I have left the tank untouched for 6 months until I decided what to do with it.  No lights no filter.  

 

Seems to me you were just curing live rock for 6 months. Bacteria on the rock doesnt need light to survive so IMO it's still live rock.