Feeling Overwhelmed

Hey all, I'm a total beginner when it comes to saltwater aquariums and though I've been able to maintain a 42 gallon tank for 6 months now, I am in quite a predicament. I now find myself with a Mandarin fish, a Feathered Starfish, 2 gorgonians and some other corals and fish. My concern is that I've wound up with these "experienced" specimens when I was only seeking something easy to keep. To add to my problems, a lot of information I seem to find is pretty old and I do know that this hobby advances a lot since then so I'm hoping I can get all my questions answered here with up to date information, especially since it seems my Feather Duster left its tube only to die, I'm worried about the well-being of everyone else.



First off, I do have live rock, I have two powerheads in place, one on each side and I do water changes once every two weeks, 12 gallons each time.



Current Stock:

2 Blue-Green Chromis

2 Pajama Cardinal Fish

2 Firefish

1 Royal Gramma

1 Mandarin Fish

1 Diamond Goby

1 Red Feathered Star

1 Fireshrimp

1 Emerald Crab

1 Turbo Snail

1 Astrea Snail



2 NPS Gorgonians

1 Red Mushroom Colony

1 Staghorn

1 Small Candy Cane Coral Colony

1 Carnation Coral



I feed the fish twice a day for two days then skip a day. I alternate between two flake food brands and mysis/brine shrimp. As for the corals, I usually feed this liquid called "Phyto-Feast" to my Gorgonians, Duster (RIP friend) and Starfish twice a day for two days then skip a day and all the corals Frozen Reef Plankton (San Francisco Bay Brand) every other day. I am going to get a Protein Skimmer tomorrow (I know, I know, I broke the one I purchased and haven't been able to replace it until now).



So here are my concerns:



1. How do you know how much you should feed your corals? I try to feed them half a block for each of them but I don't know if that's too much or too often. I have no idea how much liquid Phyto Feast I should feed my corals. Am I at least on the right track with what I am feeding them? Do they require more variation?



2. My Gorgonians are constantly covered in algae. I've read that you should remove them with a brush but it seems like I have to do it every three days or it gets out of hand. Is this normal? What type of brush should I use? I've used a new toothbrush but it feels way too abrasive at times. I really want to prevent this algae from growing and suspect it may be from feeding them too much Phyto Feast but I'm never sure how much I should even give them. Yes, I do spot feed. I've also had small parts of my yellow gorgonian that turned red fall off. I've "replanted" them in my tank and they seem to be doing great and I've read that Gorgonians are hardy once properly taken care of. How can I stop the tissue deterioration in my gorgonian (it isn't a lot) and help my small bits of gorgonians survive?



3. Everything I've looked up so far tells me that Red Feathered Starfish are the hardest to keep. Great, I was told they were filter feeders >_> So far it seems to react alright to the Phytoplankton and the Plankton I give to the corals, hasn't lost a leg or anything like that. It's been slightly more active recently. What do you feed these guys? The only thing I've really gathered about them is that they also do well with Krill Juice.



4. My live rocks are covered in a fine dust which appears to be diatoms. I've read some solutions such as blasting them with a powerhead every time you do a water change to using a turkey baster. I've been using my baster to clear them so far but they always seem to be covered in that stuff. Is there anything that eats them? I know my Goby takes care of what falls in the sand, but this fine dust is getting out of hand!



5. How are you supposed to clean Turbo Snail poop up? I keep seeing it and don't mind it too much since he keeps my tank glass clean but I always read that you're supposed to pick it up when doing the water change. Problem is that I don't have enough suction or even space most of the time to reach it. Most of the space is taken by the live rocks so it doesn't allow me much room to maneuver and get it. Is leaving it there fine?



6. One of the mushrooms in my colony just left the rock. It sucks because it now looks ugly and bare. Why did it leave all of a sudden? I know some of the diatoms fell on it when I was cleaning the rocks but I tried to clean it up. I put it back on the rock because I was afraid it shouldn't have left but I am concerned about it...



7. My Mandarin fish has been alive in my tank for 3 months now and I usually see it nibbling at something in the rocks. I haven't really seen it eat any of the flakes or mysis shrimp but he seems pretty active and happy otherwise. I have read conflicting accounts about how hard they are to keep but it seems that nowadays they're much easier for them to survive than before. I've considered setting up a Mandarin Diner for him but I'm afraid that my Goby will also make use of it. First off, should I just leave well enough alone or should I be concerned that my Mandarin fish isn't getting enough to eat?



8. How often should I test my water, especially with all these experienced-only corals?



I'm really sorry for bombarding you all with all these questions that are extremely broad, but any help at all will be greatly appreciated. I'm feeling extremely overwhelmed at the moment since I didn't realize I was getting so many experienced-only specimens (I asked the fish store for beginner things...) and with all the different, conflicting or inconclusive information I read online, I figured the best way to get answers would just be to ask myself.



I am extremely committed to making this tank work. I don't mind doing any additional work, buying different types of foods for my different corals, etc. I just want everyone in my tank to be happy. Thank you so much for reading and taking the time to respond.