So I've started vacuuming my sand bed as best I can, but I cant reach all of it due to rock work. Most of the sand thats exposed does get vacuumed. I dont feed heavy by all means, and I've lost several fish recently so the amount of food needing to be fed has been minimal. I do supplement nitrate and phosphate but my levels only get between 4 - 8 ppm nitrate and 0.1 - 0.5 ppm phosphate. The detritus just tends to build up on the macros, especially in the DT, despite having my MP40 and MP10 pumps going pretty good. Ive added a lot of carbon to try and pull out organics with additional skimming and thats only helped minimally.
Heres what I think is happening. My macros in the refugium grow well under a new LED grow bulb. I then take the extras thats have been getting bigger and putting them in the top DT. My LEDs on the top DT have become bad (I think) so the LEDs just dont produce enough of the right kind of light and the plants grow/wither slowly. I have gracilaria hayi, bryothamnion, codium, gracilaria, Cymopolia barbata, red grape, and galaxaura in the DT. None seem to grow well. The bryothmion is at the bottom of the tank near high flow areas, and I cant tell its grown at all, it just get algae all over it so Im constantly having to scrub it (huge huge pain). The barbata kind of grows off and on. The red grape had all the grapes drop off and now is just started to produce more (its at the bottom too). The Hayi and galaxaura where higher up in high flow areas, same thing for them. So as the DT plants dont do well, the excess nutrients causes cyano to flourish in the refugium (it grows really close to the grow light). Eventually it starts growing on the refugium plants, they get choked off, die and add more nutrients. I then do the chemiclean and kill off the cyano and repeat for a week.
I try removing the cyano in the refugium, I wipe it off the walls etc. It just starts growing on all the plants, and I cant vaccum it off. It seems doing a freshwater dip of the plants will kill it bc the bacteria is so sticky.