Corals dying - is it salinity, phos, or alk?

[over0066]

I recently had a blasto and jf favites recede and die within about 3 days. Found amphipods all over them. Want to blame the amphipods, but know its probably my fault. My trumpet corals, monti plate, and other cyphastrea also don't look great. My platygyra, other favites, mushrooms, acan, zoas, and monti digitata look good.

I ran out of original salt and changed to red sea coral pro based on their calculator and recommendation. I have already gone through 5 water changes with this salt. The die off may be correlated with a new batch of salt I mixed (20g tank, I mix 25-30 gallons of salt at at time and do roughly 5 gallon water changes). Below are my test results

10/05
nitrate 2
salinity 1.025
calcium 390
magnesium 1400
alkalinity 8.3
phosphate 0.53

10/11
Water Change (first of new batch)

10/13
nitrate 3
salinity 1.024
calcium 430
magnesium 1440
alkalinity 8.6
phosphate 0.31

10/15
amphipods all over the favites and blasto

10/16
blasto and favites gone : (

10/17
nitrate 1
salinity 1.024
calcium 410
magnesium 1400
alkalinity (ran out of reagent)
phosphate 0.25

10/18
Water Change

10/20
nitrate 1
salinity 1.024
calcium 430
magnesium 1490
alkalinity 8.5
phosphate 0.24


I always check my salinity to match before the water change. Just got a Hanna digital temp/salinity tester a few days ago and it is reading lower (1.022 vs 1.024) than the refractometer which has been calibrated.


I can't decide if my coral die off is from:
1. alk changes with the coral pro salt (which is supposed to be alk of 11.5, but I haven't checked it)
2. salinity being lower than I thought
3. phos dropping too fast

What do I do?
1. Dump my 20 gallons of red sea coral pro saltwater and change to the regular red sea salt
2. Follow my digital salinity tester and increase the salinity of my tank (probably needs a bump anyway, but not sure if 1.022 is problematic if that is the accurate number)
3. Get on better schedule. I think I will be testing sunday evenings. Water change monday, and testing again tuesday or wednesday for a while until I am comfortable again.


Any help would be appreciated, thank you!

 

[Spare time]

0 nitrate and high phosphate is a bad combo for coral health. You need to raise the nitrate and lower phosphate.

 

[Spare time]

Also coral pro mixes at 1.026 with half a cup of salt per gallon

 

[mdb_talon]

For the salinity i would trust a calibrated refractometer over hanna anyday. Have you went back and tested with calibration solution again to confirm it still correct? If it is seems that is the correct number unless your calibration fluid is off.

I personally dont think phosphate dropping fast would have cause the death of those two. I also dont see that your alk has went up any significant amount. Certainly not enough to kill those coral.

If i were you my priority would be figuring out what your salinity actually is and going from there.

 

[Shirak]

What are you using to calibrate your refractometer? I also found the DIY solutions for refractometers and digital meters from Randy very useful!

Your Ca, Mg, and Alk seem decent so I am guessing it's not salinity even if it's down a bit from NSW. Nitrates seem low. How old is the tank and how long have you had the corals that are not looking good?

 

[cww81]

I'm almost positive that the amphipods are not the culprit and are just eating off the dead tissue of the corals. The high phosphate is concerning and its good you took steps to fix it. LPS like some nitrate and phosphates to be in the water so I would recommend around 0.1 or less phosphate and 5 nitrate. If the digital salinity probe came with a calibration solution and you calibrated it with that I would assume it to be correct. You can also use 100% pure RODI water to calibrate the refractometer, just set it to 1.000 specific gravity or 0 ppt. I also don’t believe the raising of alk to be a problem because anything under 1ppm per day is ok. If the salinity, nitrate, and phosphate are in check I would then check things such as lighting and flow(too much/little). Hope that helps

 

[over0066]

What are you using to calibrate your refractometer? I also found the DIY solutions for refractometers and digital meters from Randy very useful!

Your Ca, Mg, and Alk seem decent so I am guessing it's not salinity even if it's down a bit from NSW. Nitrates seem low. How old is the tank and how long have you had the corals that are not looking good?

Tank started up in February. Those corals that died have been there for about 3 months. The favites actually had grown significantly, spreading on the rock around it, then receded over the course of a week and was gone. Blasto would open and look great (it was only one polyp), would eat food given directly to it. At the same time the favites died, the blasto died.

In my attempt to get the phosphate lower, I have dropped the nitrate to 1. I have a bag of GFO in the media caddy in the back which seems to help, but the weekly water change helps the phos the most, but drops the nitrate as well.

 

[Shirak]

Tank started up in February. Those corals that died have been there for about 3 months. The favites actually had grown significantly, spreading on the rock around it, then receded over the course of a week and was gone. Blasto would open and look great (it was only one polyp), would eat food given directly to it. At the same time the favites died, the blasto died.

In my attempt to get the phosphate lower, I have dropped the nitrate to 1. I have a bag of GFO in the media caddy in the back which seems to help, but the weekly water change helps the phos the most, but drops the nitrate as well.

What have you been feeding? Sounds like things were going well initially and then something changed when you started battling the phosphate. Did you cut back on feeding? Some foods are particularly high in phosphate. I would look into that. Water changes will drop nitrates also so better off continuing with the gfo. You could also get some nitrate supplement to help bump just the nitrates

Regarding refractometer calibration, Randy has stated many times, calibrating an inexpensive brine refractometer with RODI will cause it to read saltwater incorrectly. Get some refractometer calibration fluid or better yet make some of Randy’s DIY calibration solutions for both your refractometer and your Hanna conductivity meter.
http://reefkeeping.com/issues/2004-06/rhf/index.htm

 

[over0066]

I calibrated the refractometer with the BRS calibration solution and the hanna checker with the hanna solution that came with it. Either way, I know my salinity is at best 1.025, so I added some concentrated salt water to the tank last night, hoping it will slowly bring the salinity up as the extra water is evaporated off.

 

[Randy Holmes-Farley]

i do not see a chemical reason for the loses. I would not be convinced it relates to the new salt water.

I doubt an alk increase of 1 dkh or so from the water changes will kill corals like this.

 

[Shirak]

I calibrated the refractometer with the BRS calibration solution and the hanna checker with the hanna solution that came with it. Either way, I know my salinity is at best 1.025, so I added some concentrated salt water to the tank last night, hoping it will slowly bring the salinity up as the extra water is evaporated off.

The BRS Refracto juice?

If so I would look to verify and suspect your Hanna is correct. Others have had issues with the BRS Refracto juice.

 

[fachatga]

I'm almost positive that the amphipods are not the culprit and are just eating off the dead tissue of the corals. The high phosphate is concerning and its good you took steps to fix it. LPS like some nitrate and phosphates to be in the water so I would recommend around 0.1 or less phosphate and 5 nitrate. If the digital salinity probe came with a calibration solution and you calibrated it with that I would assume it to be correct. You can also use 100% pure RODI water to calibrate the refractometer, just set it to 1.000 specific gravity or 0 ppt. I also don’t believe the raising of alk to be a problem because anything under 1ppm per day is ok. If the salinity, nitrate, and phosphate are in check I would then check things such as lighting and flow(too much/little). Hope that helps

I’m going to disagree here. You can’t calibrate refractometer to 1.0 using plain water. It doesn’t mean it’s calibrated to get 1.0 with RODI. Make Randy’s solution rather than something bought would be my recommendation.

 

[over0066]

I feed TDO chroma boost pellets on a timer twice a day and 3 times a week I do frozen brine shrimp or mysis with rotifers. Nothing else has changed in over 2 months. Is it possible I need to clean out my water storage bins? Do they breed badness that kills?

 

[Randy Holmes-Farley]

Is it possible I need to clean out my water storage bins? Do they breed badness that kills?

I do not think water storage containers breeding bacteria is a likely problem for corals.

 

[Cory]

Anything rusting anywhere outside and in your tank? Check pump magnets for swelling and rust. It isnt the iron thats a problem but the other metals in rust that causes losses. Even if you have an led which has rust it can enter your tank.

 

[over0066]

I appreciate everybody's help. I have corrected the salinity with the hanna readings since it does not use the potentially problematic BRS solution. I intend to make my own solution as suggested above, and calibrate both instruments to the same solution.

Unfortunately that leaves me without any answers. I still have corals that look awful, but my trumpets may be showing signs of life again. I guess I am going to assume I contaminated the water somehow. I don't see any rust on any components, but that type of contamination is the best explanation I can see. I wonder if I had something on my hands? I have fairly new carbon in my media basket, but maybe I should change that out to be sure.

Again, thank you all for your help!

 

[Shirak]

Maybe post some photos of your corals under white light? Doing a water change and refreshing the carbon shouldn't hurt but I would be looking more at water parameter swings or something else like nutrient levels or par levels. You could also do an ICP water test just to make sure there isn't anything funky going on like heavy metals.

The DIY calibration solutions are pretty easy to make. Just be aware you will need one for the refractometer and a different one for the Hanna electronic pen. I have a jar of each I keep handy to check whichever meter I am using. As long as it's not left open or diluted when using and kept tightly sealed between use it will last a long long time.

 

[willieboy240]

Have you tested your water for copper ?

 

[over0066]

I do not have a copper tester. I figured there is no way it would get in the system unless I did it intentionally, but maybe I should test anyway? Might just be time for an ICP test.

I have brought up the salinity a bit, and plan to make my own calibration solution tonight and verify what I am doing. Will also retest everything this evening to see where I am at.

I am still in the same situation as a whole. Frogspawn looks good, WWC Bejeweled Favites is expanding and looking great, Acan look great, Green Hairy Mushrooms looking healthy, GSP is expanding, Digi looks ok, 2 zoa colonies look good, 2 other colonies look ok, but may have lost a polyp or two.

On the other hand, the WWC peppermint cyphastrea looks like it is receding, platygyra looks tough, may be dying, plating monti doesn't look good, stylo has lost most polyps near its base, Candy canes don't look good, but showing more life than before.

Just in case the amphipods my be causing a problem, we did add a captive bred green mandarin last week. Seems to be doing well. Looks beautiful, but is quite small. (the honest truth is the family doesn't like seeing all the pods crawling everywhere, so hopefully this guy will decrease that a bit over time).

Here are some pics for reference.

 

[Randy Holmes-Farley]

Chemistry issues may not be the most common cause of coral problems (contrary to popular belief, IMO), but an ICP test could be useful to rule out chemical issues for things you cannot readily test.