75 gal RR ups and downs

[Markster]

I have had my 75 gal RR going since 2003 with not too many issues until late last year and most of my corals (hard and soft) that I had for years died off. I used to be able to keep inverts (mainly shrimp, snails and crabs) for months if not years without any problem. Over the last two years, I cannot keep any of thes alive for more than 48 hours.

I do a 10% water change every Sunday, run a protein skimmer and UV sterializer every day. I have a Ca reactor and 30 gal sump. I utilize two 175w 10k MH, 2 65w 10k PC and 2 65w Actinic PC and on timers. I got out of testing the water since everything looked great and no issues. Just before my second deployment to Iraq last October, the tank began a downward spiral and I lost all corals. The rock was completed covered with hair green algae. I keep three to five fish and always seem to get down to three fish for a long period of time. I keep a Tang, Clown and Foxface currently. I hired someone to take care of the tank duing my deployment and when I came back in February, I took the chance to restock the tank with small pieces of coral and many of them. I scrubbed the rock and within two months the rock had great corraline algea growth and the corals looked great. In the last month and a half, the cycle began again and the rock began to be covered with red slime algae so I treated with chemiclean. That took care of that then I got dark green non-hair algae. I have been using AlgaeFix and using phosguard, carbon or optigel in the sump. I use a RO/DI unit and that has been installed since 2002.

I feed once a day with algae strips for the Tang and Foxface and then a small mixture of frozen food for all of them.

The zoos and some soft corals are doing okay. The mushrooms exploded so I scrubbed them. I have getting a bright green algae growth now.

I am in between tearing the tank town again and scubbing the rock, going to just a fish setup with some rocks only, or just tearing the entire thing down and selling it. I just bought all new bulbs which I would be changing next week as I do annually.

I have been testing again and the phosphates are not existend, Ca at 220 and I have been supplementing with Turbo Calcium and it does not seem to be moving up. I was using an older Salifert test kit and just bought a new kit and it shows the same value. The alk is 2.5 and pH 8.0. Spec gravity is 1.024 and I keep the temp around 82.

[ErikH]

Too many nutrients bound up in your rocks, if I had to take a stab at it. Check your Mag levels and have your Ca and alk double checked at a LFS.

Take that rock out and put it in FW. Leave it there until the HA is gone. Treat with algae fix and let it sit for a week. Bake your rocks in the oven at 350 for a day. 10% bleach solution and let the rocks sit in that with FW for a week. Let it dry for a week in the sun. Bake it again. Let sit in FW for 2 weeks in the hot sun. Take it inside, and put it in some SW buckets with powerheads. Change the water weekly for a month. After that's done, put some crabs and shrimp in there. See how they fare. <-- I have never done this, or had to, but it's what I would do.

Or, buy some new rock and try again. Replace your sandbed as well. Remember, not all phosphates show up on tests. I'm sure there are plenty of other things that algaes can thrive on in different combinations. The ocean is the least explored, most complicated thing we have ever encountered. You always have to remember that. :)

[alton]

Start doing 20 gallon or 30% water changes once a week, checking your TDS from your R/O System to make sure your make up water is good. You need to get your calcium and Mag levels up hopefully water changes will take care of this in time. Remember your tank did not get that bad over night it took years and will take at least 6 months to straighten out. Next two choices, either softies like Xenia and GSP, and or a phosban reactor with phosban to remove undectectable phosphates. That is what I call them when you buy a test kit and everything looks good but you still have hair algae? Good luck just remember it will take months to change your tank

[Europhyllia]

I would say Calcium needs to go up before you add coral.
I read an article not too long ago on how Alkalinity goes up or down much more easily than Calcium levels.
If it's really that super low it may take a lot to get it back up.
The big water changes Alton suggested should help.
I just plugged your number into the reef calculator:
http://reef.diesyst.com/flashcalc/flashcalc.html
Not surprisingly it does look like you will need quite a bit to get the calcium back to normal (and then adjust alk to match it)
I'd probably go for a really big water change or two.
If it's that depleted of calcium it may very well lack other things that you are not testing as well.
http://www.reefkeeping.com/issues/2002-04/rhf/feature/index.php

Hope I didn't offend you by posting all these links. Clearly you've been doing saltwater a long time and have access to the internet too lol but the calculator and the Randy-Holmes-Farley pages are some of my favorites so I wanted to post them in case you don't have them bookmarked or haven't see them.

What TDS reading does your RO have?

[Markster]

I did a reference test on a new Ca test kit and it states 470 on the bottle but was near 100. That is the same result I received on the actual tank sample. I tested phosphate which was practically zero, nitrates were also near zero. I have a Red Sea Mg test kit and it never changed to the blue color. I also tested alk again and it was 2.5. When I read the article, it states a relationship between Ca and alk and I would think if my Ca is really that low the alk would not be as high. I am going to do another large water change today. I added two turbo snails, two emerald crabs, one coral banded shrimp, sand shifter starfish and a pencil urchin. Both snails did not make it, only one of the emeralds is still going, the shrimp died over night, the starfish is still going and the urchin died. The zoos, softies, cabbage coral, yellow polyps, button polyps look good. The three fish are doing fine also. I have one two headed torch coral and it has not come out for a few days and only a little bit when I first added it. I am hesitant to pull out all the rock, bleach etc. and replace the sand bed.

I am going to have the water tested at the LFS before doing a significant action such as that. Thanks for your assistance.

[Markster]

Quick update. I did remove 35 pounds of live rock but left 20 pounds in the tank. This allowed me to siphon the sandbed thoroughly and roughly did 20 gallons worth of dark brown water change. I did add some new arogonite ontop of the sandbed and mixed it a little. This was a three day process and after the tank cleared, I added a some more fish and a cleaner shrimp. As of today, nearly a week later, all are still living and the two snails I added are cleaning the rock of any left algae and so are the two tangs and angel that were added. The tank looks much better and really like the additional swimming area that I created not to mention I did not build the rock up against the back of the tank so now I can see all around the rock and it creates a great swimming channel. Thanks for the recommendations.