Hi,
i have now been running a scrubber for just under a year and have been skimmerless for 6 months. I have had a dsb in my sump for 2 years and have never seen my nitrates below 20. After installing the scrubber they went down to about 5 but have been gradually increasing over the past few months to 30 now. I have noticed a black layer in my dsb about 2in down and am wondering if this is the cause of my high nitrates.
My local lfs told me to stir up the dsb but I was under the impression they shouldn't be disturbed.....so question is do I :-
1,stir up the dsb in the hopes nothing worse will enter the water
2, syphon a bit of the sand bed up
3, completely remove the dsb
4, something else?
Thanks in advance guys