Can anyone help me with my dying coral problem?

[Lightwaveguy]

I have run the same 55 gal tank for over 17 years now. I do an 18 gal water change every month. I use Instant Oceans reef crystals salt mix. I use a Marine Land Tide pool sump with the SOS overflow. I use a Magdrive 1800 GPH pump in the sump and ¾ PVC piping back up to the tank. There is a wave generator in the opposite side of the tank from the sump return. I run mechanical and chemical filter pads in the trays, charcoal, ammonia, phosphates and nitrate pads, plus active charcoal with nitrate removal in a bag in one of the trays. I also use Seachem Purigen in bags in the sump. I change out the filter pads and Purigen every other month. I do not use additives because I do the monthly water changes that restore the essential elements.

I use a Sea Clone 150 skimmer. I have a Current LED lighting system. My temp is 77.5 to 78. Density is kept at 1.024 and I test all basic parameters and they are all in range except for a slightly elevated nitrate level. My straight tap water has this elevated nitrate level. I use ROM water for all top offs and water changes. I have a 2.5 gallon refugium that runs opposite the main tank lighting schedule. Lots of plants and algae in there, doing very well.

The tank is made up of over 100 Lbs of real coral, I’ve had some of these pieces for 30 years now, and various forms of live rock, volcanic and Fuji.

I have lots of crabs, snails, a few anemones and other invertebrates, starfish and what not, 12 or so fish, clowns, two large engineering gobies, they mix the substrate on a regular biases, a few damsels, a few wrasses, an angel or two and a few tangs. I think there is a shrimp or two in there too, but they hide very well, sometimes you see them, sometimes you don’t. There are sponges growing in one corner, don’t even know where they came from. Feather dusters all over, little ones but lots of them. I do have red or purple and green algae on the sides and back of the tank, probably due the elevated nitrates. The snails do a good job of keeping up with it, but something eats a lot of the snails and I have to keep adding them. The engineer gobies bring all the shells to one spot and stack them up for me, they like a neat tank. Lots of Copepods too.

I think that covers my setup.

So my issue is recently is started to add coral, all different kinds. Frog spawn, LPS, SPS, Mushroom, Polyps, but they will only last a month or two tops. They go good for the first month or so then start to fade. Everything else in the tank does very well, some of the fish are 10 years old or more.

Can anyone offer any insight or help?

[thegrun]

A couple of things jump out as possible causes, but giving us actual test results are very important in diagnosis. "Within range" gives us very little to work with, please list all your known test results. How high are your nitrates? So here are a few things to consider:
Raise your salinity to 1.026, corals do best at natural seawater salinity, some will not survive at all at lower salinity.
Filter pads need to be changed or cleaned every 4 days or they will lead to higher nitrates.
Volcanic rock almost always contains heavy metals that will leach into the water and kill corals. The contamination may not be bad enough to kill your shrimp which are also sensitive to metals, but still heavy enough to kill coral.
How many watts is your lighting system, what colors are the emitters and how many watts each are they? It may not be providing enough light.

[A sea K]

For one, a better skimmer will help with your nitrate problem. It will remove more organics before it is converted to nitrate. Another issue I see, are you dosing anything at all to maintain your Ca/Alk/Mag? If not then you will benefit from more frequent water changes to help maintain consistant levels. Large monthly w/c will wreak havoc with sensitive coral if you have no other means of keeping stable parameters.

[homer1475]

Maybe I'm stupid, but WTH is ROM water? Reverse osmosis? RO no DI?

[SnowManSnow1]

Imo you can simplify that system and get better results.


Sent from my iPhone using Tapatalk Pro

[Sk8r]

Your alkalinity should be 8.3. If they are stony coral, your mg should be 1350 and your calcium 420, never wobbling. If your nitrate is over 5, that could be a reason. YOur lighting could be a reason. Your positioning of the corals for light could be a reason. THere are others, but these are a good start on common problems.