Bad optical sensor

[edolan]

I have lost several corals over the last few months including a birdsnest and digitata. My hammer coral and frogspawn aren't opening up like they used too. It looks like my two acans are dying as well. A couple of my zoa's are hanging in there while the others seem to be receding. I have been doing regular water changes and maintenance. A couple of weeks ago one of the optical sensors quit on me and I have been meaning to replace it. In the mean time I have been using the high level sensor to run the ATO. I pulled the ATO today to remove the bad sensor and I noticed a brownish color which seemed to be leeching from the seam where the wire for the sensor meets the actual optical sensor. This sensor was actually always submerged. I am assuming that the wire itself is copper? There was a tiny amount of visible corrosion but I have no idea how long it could have been corroding before the sensor actually gave out. Is it possible that this is the source of my trouble?

 

[Flippers4pups]

Could be.

Any water parameter swings?

 

[edolan]

I did have a weird experience with a bucket of instant ocean salt where the magnesium starting rising. It got as high as 1500 ppm on my Red Sea test kit. I tested a fresh mixed batch before I put it in the tank and it tested off the chart. I thought I possibly had a bad test kit so I opened up a fresh bucket and retested and if I remember correctly it came out normal around 1300. Currently the tank is at around 1440 as it is slowly correcting through water changes.
Otherwise
Alk is 8.0 Hannah test
Cal 420 Redsea test
Nitrate 0 with API test
Phosphate 0 Salifert test

 

[homer1475]

Mag is not the problem. When battling bryopsis people use to use Kent Tech M to raise it way over 1600 and no one had any issues, heck even now with using regular IO my mag is up over 1500 with 0 problems.

If I had to guess by your parameters, with 0 nitrates and 0 phophates your starving your corals to death.

Could be a tiny mount of copper in the system, but I don't think that tiny amount would cause the problems your seeing. An ICP test, or hanna copper test would rule out the copper though.

 

[edolan]

If I had to guess by your parameters, with 0 nitrates and 0 phophates your starving your corals to death.

I have to admit I have had a complete misunderstanding on the importance of nitrate and phosphate in a reef tank. I always just thought of it in terms of algae prevention and not as required nutrients for corals. Two years into this hobby and this seems like something I should have learned. I have barely ever tested for nitrate or phosphate.
I am ordering new test kits and I will confirm that they are actually at zero. Assuming though that they are at zero, what is the best way to raise nitrate and phosphate . Should I stop doing water changes, feed more, dose...? I had some hair algae so I just figured that was absorbing the nitrate and phosphate and messing with my test results but now I am not sure. Thanks for any advice

 

[Saltyreef]

Its ok. I didnt understand the concept either until about 5 years in lol.