Coral growth and coloration

[Bioaquarium]

Hello everyone,

I have been reading and studying on this topic for so long but despite my efforts i still cant keep healthy and colourful sps. I have problem with some lps too. Softies do pretty well.
I have a Red Sea Reefer 170, i moved from a smaller system about 4 months ago. I had it for 1 year and a half (in which i had the exact same problem) for lighting i have the Ocean Revive leds at 30% blue and 10% whites, i have measured the PAR output and it is around 350 to 150 top to bottom. For flow i use a jebao rw-4 wich gives me around 40 times the volume of the tank per hour. In sump i have a coral box skimmer for roughly 300 liter and some carbon inside the filter sock. I have a dosing pump to replenish KH, Ca and Mg, and the values are really stable. I do 10% water changes monthly. I have done an ICP test recently and i had all parameters in good ranges except for Iodine which was pretty low. I have started dosing it and i will test it again soon. I recently added some Miracle Mud in the sump in the attempt to replenish all the elements slowly. I do not dose bacteria since the beginning of the system.
these are the parameters tested last week

salinity 1025
KH 8
Ca 430 mg/l
Mg 1290 mg/l
PO4 0,02 mg/l
NO3 4-8 mg/l

I have only 4 fish right now cos i had an ich outbreak about a month ago so I'm not adding anything else right now. I have a cleaner shrimp and many turbo snails. I feed twice a day different pellets.
Here are some pictures of the display, i will add some pictures of the sump too.
A month ago i have added 4 new corals, a healty deep purple milka, a orange montipora, a green caulastrea and a green motipora. All of them are slowly losing color and vibrancy. Strange thing is that some sps seems to do fine (for fine i mean not losing color and growing very very slowly) like a red motipora digitata and one anacropora. I have also a green pavona catctus which i thought it was dead but now is getting is color again. Regarding soft corals i can't complain, they grow, slowly but they do grow. The colors are not awesome but atleast they dont die. In conclusion i would say that in my tanks I never saw the colors and growth I expected, especially from sps and lps. I do not consider myself an expert but i'm not really new in the hobby. I am a chemist and i try to read as much as i can on different topics related to the hobby. But after 2 years i am starting to feel frustrated. What can i do better? Should i have just more patience?
Thank you very much
Carlo

 

[Super Fly]

what is temp and acclimation method being used?... One thing I notice is there are no coralline algae in your tank, which is a sign of good water environment & values that promote coral growth.

 

[jda]

You might get some more focused help in the SPS forum, but just at a quick glance, the N and P are fine to grow coral and have good color (some, but not too much). Flow seems fine. I see enough coralline on the bottom to indicate that you have had a good run of it growing. OR fixtures are not known to give the absolute best SPS coloration, but you should at least have good color. My quick recommendation would be to add some T5s to the ORs like so many others have done - they nearly all love this addition and wish that they would have done it sooner.

 

[Bioaquarium]

what is temp and acclimation method being used?... One thing I notice is there are no coralline algae in your tank, which is a sign of good water environment & values that promote coral growth.

Temperature is 26° Celsius, very small changes during day and night, for acclimation, i always buy from lfs or other hobbists, so the time in the bag is pretty short, anyway i float the bag, then gradyally add water, the process takes about 30 mins usually. Coralline algae are growing, they are not much probably cos i moved into this tank about 4 months ago

 

[BertieBones]

what is temp and acclimation method being used?... One thing I notice is there are no coralline algae in your tank, which is a sign of good water environment & values that promote coral growth.

Can I just ask why that's a sign of good water for coral growth?

 

[Cory]

Slowly losing color generally means bleaching. At one point i had a montipora bleach. Usually temperature causes bleaching. Turns out for me it was low potassium at 300. Maybe check potassium. I also had a mirror in the water that might have been adding silver/aluminum to the water. Also i had a large ats with 0no3/po4. Some things to consider. Maybe do an icp analysis by triton.