Can't get LPS or SPS to grow much

[EEE1986]

Hello,
I was hoping you all could help me with achieving better growth with my LPS/SPS. For these type of corals I have small frags of the following: red montipora digitata, cali tort acropora, pocillopora, a hammer, a torch, a chalice, a war favites, a frankenstein leptastrea, a dragon soul favia and one mardi gras acan. Some of these have been in my tank for several months now and any growth I've seen has been incremental if at all present. The coral are still very much alive and show good polyp/tentacle extension but just wont grow much. In the meantime I have seen decent growth with my softies (xenia, GSP, zoas, mushrooms). The only softie that is not really showing growth although I have only had it a month is my toadstool leather. I am currently running a fluval evo with an AI prime set at settings recommended on the AI facebook group (Pennywise AB Saxby). For flow I have the stock return pump with random flow generators and an AI Nero 3 set at random with high variability and a max speed of 35% and a minimum of 1%. I perform weekly 10% water changes with LFS supplied saltwater and started adding Kalkwasser to my ATO 1.5 weeks ago. I feed reef roids mixed with TDO pellets 2-3x a week. I placed my SPS near the top of the tank where PAR and flow should be abundant. I have one clownfish in the tank and a wide variety of inverts (shrimps, snails, crabs). My water parameters at last measurement were the following (I measure Nitrates and Phosphates before changing water and Ca, Mg and KH post water change):

Salinity: 1.025
pH 7.8
Nitrate 5ppm
Phosphate 0.05ppm
Ca 350ppm
Mg 1220ppm
KH 8.2

I plan on increasing the amount of Kalkwasser added to my ATO to bump up the Ca, KH and pH. I realize my Mg could be higher as well and I have Red Sea Mg available if I you think it would be worthwhile it's just hard for me to dose it daily as I travel a lot and work odd hours. I also have All For Reef but I have the same issue with dosing this that I do for Mg. Any advice would be greatly appreciated.

 

[Mr. Mojo Rising]

What percentage is your light running on? Corals surviving but not thriving when parameters are fine almost always come down to low lights.

I have AI prime on my 15 gallon set at 80% for mostly zoa's and mushrooms. On your size tank, if you want sps, the intensity should be approx 80%-90% IMO. Just judging from the graph, looks like yours are set low.

 

[EEE1986]

Interesting thought. I didn't even consider that as a possibility as I actually semi-bleached the lepto when I placed it towards the top of the rocks so if anything I thought it was too high. I have attached photos of my percentages at peak at at the beginning of the day. At peak it's pretty high but it's not that high for a prolonged period of time I guess. I'm open to other recommendations for lighting schedules perfect for a mixed reef tank like mine if this one is insufficient.

 

[AmateurAlchemist]

Get your Ca up and stable, then re-evaluate. I've had frags, particularly SPS, sit idle for months then just explode overnight. LPS grow slowly, it's their best and worst quality. If corals are out and generally happy, I'd make calculated, small changes as slowly as possible.

 

[VintageReefer]

On ai prime that uv channel is known for melting the lens when run over 100%. I wouldn’t let it go over 80%

It’s also a fairly weak light, but has potential. 60-85% is it’s sweet spot. Anything below isn’t really strong enough, anything above risks melted lens.

Looks like 50% of your schedule or more is outside it’s ideal zone.

 

[Mr. Mojo Rising]

Turn the uv down, as mentioned above you can melt the lense, do a search on it.

Looks like your peak is rather short... I leave my lights at 80% for 10 hours (one hour ramp up and down)

 

[EEE1986]

Turn the uv down, as mentioned above you can melt the lense, do a search on it.

Looks like your peak is rather short... I leave my lights at 80% for 10 hours (one hour ramp up and down)

So you have your UV and blues all on at 80% across the board? Any greens reds or whites?

 

[BryanM]

I use different lights, but also have them on 12 hours, 1 hr ramp up and down, so 10 hours at peak setting.

 

[Mr. Mojo Rising]

So you have your UV and blues all on at 80% across the board? Any greens reds or whites?

Blue, violet and royal blue at 80%, uv at 70%, red and green at 10%, and whites at 25%