Its more then one thing going on in the tank.. You say there where bubbles there before the sponge removal that was just an early sign the problem was already in place and waiting for a kick start and removal of the sponge may have lowed the NO'3 right up front But by its removal its allowing more solids to pass through and settle out .
And now there is more of what was some what lacking for the Cyano issue. I understand the frustration I have been there myself. NO'3 are not the worse thing to happen to a system Its really a sign the filtration is working as its supposed to NO3s are just the last link in the total de-nitrification process .
You need good strong skimming and strong water movement. L/R is not a magic bullet they also need certain parameters to live and function properly . dd the sponge and clean the sand with a good power filter. Like a diatom and stir the sand and get all the trapped waste up into the water column and filter out solid waste.
NO'3 are being produced there in the C.C its full of denitryfing bacteria doing their job at the site of the problem. As they used to do on the sponge that sponge acted as bio balls do and since that was removed the bacteria went with the sponge until it just recolonized into the C.C Its bacteria doing its natural job. They will show up as needed and High NO'3s are the sign they are needed.
The end of the nitrafication process is what spawned the DSB and Plenum ideas. But the bare Berlin took care of the process via a very strong skimmer and lots or rock and lots of fast and strong water movement.
Other's fighting this same problem is what spanwned all of these filtration processes I like good skimming fast water and plenty of rock shallow sand in tank refugium with DSB and plants and a coil denitrator and carbon to do the job for me. Its all a trade off to one for the other. _________ Some of the world's greatest feats were accomplished by people not smart enough to know they were impossible (Doug Larson) |