Want to add new live rock

do u think adding new live rock to my mature setup is a good idea ?I am running a 290L setup on about 15kg of fiji , want to add another 30kg ??

 

If you can, cycle it in a large container with salty water, a heater and a powerhead, failing that, i would add no more than 10% of your tank rock at a time, so to start with, add 1.5kgs, allow it to mature with the liverock already present as that will be able to cope with the ammonia spike without damaging your fish/corals.

 

what do u mean by 'failing that'?

 

I mean that if you cannot put the 30kgs rock into a large enough container to cycle it, then use the other method of adding 10% at a time. If you added 30kgs of rock to 15kgs of mature rock then there would be a large cycle and ammonia spike, which would harm and possibly kill your tank's livestock.

 

I have a 50L tank I can use.how long should they cycle for? how much can I cycle in this tank?Should there be lighting or not ?

 

maybe about fours hours of light a day? try and avoid an algal bloom? correct wee man?

 

Yep - well near enough, reducing the light whilst cycling only serves to slow the cycle, run it for around a month testing for ammonia, nitrite, nitrate and phosphate daily, keep the water topped up with R/O - just like your display tank, when the cycle is complete, then move it to the new tank/ scape it and follow that up with a decent water change (say 20%) as moving your current rock about may release trapped detritus and dirty your water, then leave it alone to allow your fish to calm down as the move will stress them.

 

Adding new (but already cured) live rock to an existing system is beneficial in keeping diversity of organisms. Be really sure as mentioned above that no phosphates or other indicators of dying life are present before adding to your tank tho.

 

I would say this is vital for mature systems, to make sure you don't get the dreaded "old tank syndrome"