Help me figure my tank out!

[toekietoekie]

Hello everyone,

After a lot of time researching, saving, convincing people and dreaming I finally converted my 1700 liter (450 gallon) freshwater aquarium into a reef tank.
The tank has now been running since august and I have seen a lot of problems allready wich I managed to slowly fix. My main problem in the beginning was phosphates wich would never stop rising, it sometimes rose 0,5 ppm in one day. I believe this was caused by me using rocks that were previously used in a malawi cichlid tank and them just leeching phosphates all the time. That problem is fixed now however! All the phosphates have been leached out and removed with lanthanum chloride and water changes. Now it sits comfortably at 0,06 ppm and stays there.

full tank shot:

My other biggest problem was, and still is, cyano. It appeared as a small spot on the sand one day and then just exploded all over my tank. I added a blue cheek goby wich eliminated the problem in a few days. I had to remove him however since he was killing of coral with all the sand he was piling on top. The cyano stayed away for a long time luckily but now it has returned. It's not as bad as it previously was but it still smothers corals every few days if I don't blast them. I'm just a bit confused as to what is causing the cyano? My water parameters are listed below.
cyano on sand and rock:


The second thing I would like help with is figuring out why some corals are not doing so well. My soft corals are all doing very good and growing well. My zoas are a different story however. Some are growing super hard while others have not produced a single new head since getting them and others are slowly diying off. Does anyone have any idea what might be causing this? My hard corals are the same story. My plerogyra is doing really well, as is my acan, but others like my fox coral, caulastrea and lobophytum have lost some tissue or are not really opening like they used to do.
soft corals doing well:

zoas, some doing very good and some slowly diying off:

hard corals, the caulastrea is giving me the most concern


stocking list:
fish:
-2 occelaris clowns
-1 royal gramma
-5 yellowtail damsels
-2 yellow coris wrasse
-1 six line wrasse
-1 orange back fairy wrasse
-1 small fox face
-1 tomini tang
-1 small convict tang
-1 small scopas tang
-1 fire fish
-2 captive bred mandarin fish (eating frozen)
-2 bangai cardinals
-1 starry blenny
- 1 pistol shrimp goby pair

inverts:
-2 cleaner shrimp
-1 sea hare
-1 sand sifting starfish
-1 collectors urchin
-1 long spined urchin
-1 tridacna clam
-3 tube anemones
- assortment of snails

my icp analysis from a few days ago:
https://lab.faunamarin.de/en/share/analysis/194919I know it's certainly not perfect but as far as I can tell it's also not terrible right?
I allready fixed the slightly low salinity so ignore that, I also added an additional powerhead for more surface agitation to lower CO2 content.

If anyone would be willing to help me figure out the problems I'm still having I would be really thankfull. I can provide more information if it's needed.

 

[Subsea]

I am not sure if I am the right person to mentor you. I have expired test kits that are unopened.

After 55 years of Reefing, I never moved away from soft corals. In general, soft corals prefer high nutrients and don’t require alkalinity management as opposed to SPS, which are much more demanding.

High co2 in water normally means that co2 in your home is high. Are you using a protein skimmer, if so, then consider drawing outside air that is lower in co2.

With respect to Cynobacteria, I suggest you use ChemiClean.

Some strains of cynobacteria using nitrogen fixation produce ammonia from dissolved nitrogen gas in the water. Also, cynobacteria mats change chemistry underneath and dissolve calcium phosphate in your substrate.

https://chemi-pure.com/products/chemiclean/