New Reefer Questions

[hockey.teacher.reefer]

Hi everyone,
I am fairly new to keeping saltwater aquariums. I have 2, a 120 gal with sump, and a 13.5 gal fluval. I have these tanks in my classroom as I am a teacher. The 120 gal was purchased from someone off Facebook marketplace and has now been established with me for about a year and 3 months. My Fluval I started on my own and has been established for about 2.5 months, fully cycled. I have mushrooms, palythoas, a bubble, and a cabbage leather in my 120 gal. I had also introduced a zoa, a green branching hammer, and a rainbow acan into my 120 gal and they didn’t do too well and started dying, so I switched them over to my 13.5 gal just to see if maybe it would help. The zoa bounced back and is now doing much better, I wouldn’t say thriving, but definitely doing better. The hammer and acan had completely died (or so I thought). I left them in there just to see and today I noticed that my acan has bounced back and is starting to grow again! My hammer is still very dead, but I’ll leave him there just to see. I also have a 55 gal freshwater tank, but that’s another story, for another forum.
Now, to the point of all this, I wanted to ask a couple of questions:
1. My cabbage has been doing not too great lately, for about the last month I’d say, it has all these white spots all over it. Doesn’t look like any fish have been eating at it, and I can’t find anything similar anywhere. Does anyone know what it might be? And how I could maybe fix it? (Picture attached) checked levels today: calcium- 510ppm; magnesium- 1440ppm; kH- 13dkh. I know my levels are on the higher side for all but magnesium, but I just did a 30% water change last Tuesday. Oh and salinity is good at 1.025 / 1.026. I dose with 20ml all for reef every Friday by hand, and 20ml AB+ every Friday as well by hand. To be honest I have no idea what the AB+ does, but the person who does the water changes for the 120 gal for me said to use it when we first set the tank up so that’s what I have been doing. No ATO on this one, I just add my own RODI water when I see it getting low in the sump, usually about once a week, 5-7 gal at a time.
2. My Fluval tank has the following parameters: calcium- 480ppm; magnesium- 1360ppm; kH- 12.6dkh; salinity low at 1.023 / 1.024. I tested these this morning. Again, I know most are on the higher side, so my question here is how do I fix it, other than by doing a 10% water change? I dose All for Reef 6ml daily. When I saw that the levels were high I stopped the dose that was supposed to go in today. I have a Sentia automatic doser and an ATO on this tank. I also have a hi fin red stripped goby and pistol shrimp pair in here that I got on Thursday, although I haven't seen the pistol in a couple days, but they did hole up together and they are both shy, so not sure if he’s just hiding or dead.
3. I want to eventually grown green star on the back wall of my 120 gal and add some pulling Xenia (I know, they both grow like weeds, but it’s in a classroom so I just need some color and movement), but I have a file fish and am afraid it will eat those corals. I got the file fish to clear out my aipstasia (which it did amazingly) and now it just eats the mysis, brine, and staple food pellets I feed, so not sure here. I also have a one spot foxface, scope tang, blood red cleaner shrimp, 2 blue legged hermits, Royal gramma, long nose hawk fish, golden headed goby sand sifter, and 2 mated clowns (well that’s what I was told, but haven’t had them mate yet in my tank). All those fish are very established (except for the Goby, but he’s been there for over a month and has been doing good, not hiding, and eating well).
I know that was a lot, but this is my first post, and I really appreciate any and all help I can get! Thank you so much in advanced (my students thank you too)!

I included pictures of all my fishy/coral-y friends too for your enjoyment as an appreciation for reading this super long post…some are older and I don’t have any hair algae anymore or really any algae other than a small amount on the live rock as seen in the file fish photo.

 

[Mr. Mojo Rising]

The 3 requirements for corals to be healthy and thrive is light, flow, and nutrients. So if corals are dying and not doing well, then one of the three is lacking. Your tanks sound like they are lightly stocked, so nutrients might be the issue, but if you can share details on the lighting, flow, and nitrate/phosphate level, it will help us help you. I don't feel you need to be dosing anything.

For the fluval tank, I don't think you need to dose anything, it sounds like there is just a few corals in there. I don't feel your levels are on the higher side, I wouldn't do anything.

I don't know what prompted you to dose AB and AFR, but for low coral load that is not growing, its just wasting money.

Personally I feel if you want gsp on the back wall, go for it. Many people will just give it away so it will cost you nothing to try. Good luck

 

[hockey.teacher.reefer]

Thank you for replying! I did a few big water changes, installed an ATO and dose on the big tank (the smaller one already had them), turned off a power head (I had 2 going), and moved some corals around and now it seems as though everything is THRIVING! I stopped dosing AB and am only dosing AFR in a smaller amount, still need to dose less but have been gradually decreasing it so as to not shock anything in the system. Oh! And the leather still has all those white dots and stuff, but it is opening more and, what do you know, it looks like it’s splitting itself in half, so I would hope the white stuff goes away when it’s done fragging itself. Here’s some progress pics :)