I've built a seperate room so that i can move my DSB from under my DT. There will be two 1000mm x 300mm x 350mm tanks one above each other. Overflow from DT to top tank with T3 skimmer, DSB and ATS above, overflow to lower tank with DSB and pumped back to DT. Now the question, can i transfer my old DSB sand to the other two new DSB's or would it be better to let it cycle threw the old one as well untill the cycle is complete then remove the old DSB.