# Cycling with live rock



## masa (Oct 19, 2013)

Hello all - I've been interested reading through the various posts I found here on going from marine reef tank to cichlids. I've got 150 litre tank with 50l sump which was a reef tank but I'm now converting to freshwater. I want to keep all the nice live rock I've got so thought giving a go using that to cycle the tank. Rocks have been out of salt water for a week, dipped in boiling water, and rinsed in freshwater few times. I think there should still be plenty of dead rotting stuff left in the rocks.

Plan is to use the live rock in the tank to build up some rock formations. I've ditched the live sand and got some play sand instead. I was also planning to fill the sump with live rock rubble I have from the reef tank sump (cleaned same way as the bigger rocks). I was going to get the cycling started with this setup and then see what kind of water I end up with before deciding on fish...

Based on the various posts I've read here above should work, although probably not ideal way to get started. I can update here the progress on how the water chemistry goes and what I end up with if anyone is interested in trying out something similar. Or can someone spot straightaway things I'm about to do wrong? I've had fish tanks for years, just not kept cichlids before.

Thanks!


----------



## triscuit (May 6, 2005)

I'm not sure what you are asking...

But, I can tell you that live rock will be safe for your tank, and that it's no problem to have it in there while cycling. However, it won't help the cycle... is that what you're asking? After drying and boiling, I doubt there's significant beneficial bacteria (let alone freshwater nitrifying bacteria). The organic matter that's left on them is unlikely to provide sufficient ammonia to get your cycle going, so if you're going for a fishless cycle, you'll still need to add ammonia.


----------



## oyster dog (Jul 2, 2013)

I agree with Triscuit. You will need to seed your tank with freswater bacteria, and i suspect you will also need to add ammonia.


----------



## masa (Oct 19, 2013)

Thanks for confirming the use of live rock this way should be fine. I thought there would still be enough dead organic matter inside the rocks to start the cycling process (including all the anemones I couldn't get rid of in the reef tank). I've got it all setup now so will leave it for few days to see if anything starts happening on the nitrite front, if not then will add some ammonia to it.


----------



## oyster dog (Jul 2, 2013)

It will be interesting to see if your live rock starts to function again as live rock in your cichlid tank. You'll keep us posted?


----------



## masa (Oct 19, 2013)

looks like the rocks are making something to happen, on day 3 ammonia reading is about 0.5ppm. I haven't added anything to the water, just straight from the tap.


----------



## GTZ (Apr 21, 2010)

Decaying organics would be my guess.


----------



## SupeDM (Jan 26, 2009)

Several years ago there was an article regarding exactly this in aquarium fish magazine. It showed that the leftover organics in live rock did release enough nutrients to cycle a tank. However this was done in a laboratory type setting and it showed no increase in the speed of cycling a tank. If i remember correctly the curve as to how the tank actually cycled was different but end result was the same. Do not add ammonia to tank untill you are seeing all 0 on tests as it can take time for the osmotic change to kill bacteria deep in the rock and it will release another spike In Ammonia and Nitrites.


----------



## masa (Oct 19, 2013)

Yes I can confirm there definitely is something in the live rocks to produce ammonia. It is day 6 now and just did some water tests; ammonia levels gone up to about 1.5ppm and also pH and the hardness gone up too (pH about 8 and 6.2 dKH). Not sure on the pH exactly, I struggle to really read the colour charts on that to get anything exact.

I've probably spoiled the 'scientific' test by seeding the filter today with some bacteria (put some Evolution Aqua PURE Aquarium balls there), but that should hopefully ensure some bacteria will get established to get things going. I also put few plants there (some type of Valisneria) because thought the tank needed something to soften the look a bit. I know those may get eaten by what ever cichlids I end up putting there but though I'll give it a try anyway. Also the light I've got is marine LED which is probably way too bright so that could be an issue too. Think I'll just try to keep the time light is on to minimum.


----------



## masa (Oct 19, 2013)

Things progressing slowly with my fishless cycle... Tank has been setup with sump etc for 11 days now, ammonia levels are still up (about 1.5-2ppm) but the last couple days some nitrite there too (0.3). I suspect the dead stuff inside the once-live rock is still continuously producing so much ammonia that the bacteria isn't quite ready to consume it all yet. Just need to wait.


----------



## triscuit (May 6, 2005)

Keep testing daily, and make sure your ammonia stays above 1 ppm to establish the cycle. The hard part about doing it this way may be determining your end point. When you run out of ammonia, how much bacteria do you have established? When you get your first zero ammonia reading, add commercial ammonia to acheive 1 ppm and see how long that takes to disappear.

Thanks for keeping us posted!


----------



## masa (Oct 19, 2013)

Day 15 and ammonia levels finally dropped, although not quite zero yet. At the same time nitrite levels shot up and are off the scale of my test kit (>3ppm). I think that must mean there has been plenty of ammonia produced by the live rock. Now just need to wait for the nitrite levels to drop and tank should be ready to go.


----------



## triscuit (May 6, 2005)

Not exactly- you need to keep adding ammonia during this stage too.


----------



## masa (Oct 19, 2013)

To finish off this thread here is one more update... Tank has finished the cycling process now and it all went fine. There was enough ammonia produced by the organic stuff inside the live rocks to get the process going and it took about 25 days to complete the cycle. I added ammonia couple times towards the end just to check how quickly it all gets converted. Now after 24h of adding dose of ammonia there is no ammonia or nitrite left.

I haven't added any chemicals into the water, but the live rocks have changed the tap water chemistry a bit so that now pH is around 8-8.5 and hardness is 6.2KH. Based on what I've read that should be ok for mbuna, which I was planning to put there. Some threads on these forums were recommending saulosi species for cichlid beginners and for this size tank so I'll see if the local fish shops have those.

As expected the rocks have lost most of the colour and are now mostly white(ish), but I think they still look good and are full of small cracks and holes for algae to grow.

Thanks for all the help and advice!


----------



## shelbynjakesdad (Mar 13, 2013)

Any pics? I would love to see your rock work!


----------



## masa (Oct 19, 2013)

Here are pics of the sump and the tank... as you can see I put some plants there but not sure how long they would last if the fish like pulling them up or eating them, but will see how that goes. The shiny box on top-right is the overflow box to the sump, unfortunately can't really hide that away.


----------



## shelbynjakesdad (Mar 13, 2013)

I like the rocks/scape, but I wonder if there is a way to hide the overflow better. Maybe paint it flat black or dark gray to match your background (Krylon Fusion) and move it behind the tall plants? Looks good though - wish I had a sump...


----------

