Tank slowly declining

[Klatt]

Hello, I have a 100G tank that has been slowly declining over the past 5 months and I cant seem to figure out why and was wondering if anyone here could point me to some possible causes. History on the tank: The tank is 2 years old, and from July of 2016 to June of 2017 I finally found the tanks sweet spot. The corals were all thriving, growing very well. I was dosing Alk and Cal with Kalkwasser in my ato water. Around June of this year I noticed about 50% of my corals were starting to struggle. And about that same time I was starting to have issues with alk and cal levels. I had been slowing adding more and more kalk into my ATO water each time I refilled the reservoir until I got the the highest recommended dose of kalk in to RODI water. I was then supplementing the kalk with sodium bicarbonate and calcium chloride to keep the levels up, but when I would miss a day or two I would create large level swings. This was the reason I assumed my corals were struggling, so I decided to upgrade my system to a two-part automated dosing system (two BRS 1.1 dosers connected to my apex). I added the dosers in July and after 3-4 weeks of dialing them in, the tank's Alk and Cal have been back to normal and consistent (9.2 dKh and 460 ppm). But I am still seeing corals struggle and die. Nothing else has been changed in the tank (except for bulb replacement on my T5s). Ive had no issues with my fish. My monti caps were the first to go, but ive also lost some of my euphyllias, and zoas are looking terrible as well.

Other levels:
Salinity 1.026
Mag 1395
Phosphate 0 (hanna ULR)
Nitrate 0 (salifert)

I use Red Sea Coral Pro Salt, and do water changes every 2-3 weeks. Ive just purchased a Triton ICP-OES test kit to check everything in the water for any other reasons for the decline. I do use No3Po4x for Nitrates. Ive seen no change in skimmers output, but I have noticed a little green cyano on the sand where i cant reach to clean the bed. Is there any other thing I should look into that may help me find my problem?

Thank you!
Joel

 

[3mm3]

My monti caps were the first to go, but ive also lost some of my euphyllias, and zoas are looking terrible as well.

Phosphate 0 (hanna ULR)
Nitrate 0 (salifert)
I do use No3Po4x for Nitrates. Ive seen no change in skimmers output, but I have noticed a little green cyano on the sand where i cant reach to clean the bed. Is there any other thing I should look into that may help me find my problem?

Thank you!
Joel

I left the parts I strongly feel is your issue. This is from an experience I had last year.
I feel your issue is nutrient level way to low.

 

[sfin52]

I agree that 0 po4 and No3 is your problem. I was running 0 po4 with heavy gfo use. My lps and soft corals weren’t growing at all. I have since started dosing po4 and my gsp have explosive growth. That’s just about a month after raising p04. The lps have become brighter and have gotten bigger and my shrooms are growing as well.

 

[chris k.]

Maybe look into your makeup water quality. Do you have a rodi system? If so how are the filters? TDS lvls. Just an idea.

 

[Klatt]

ok, so maybe back way off on the nopox? i went to carbon dosing after a gigantic hair algae problem, but that problem has since been completely cleaned out.

 

[Klatt]

i do have a RODI system. filters were replaced this summer, incoming TDS is 5 (good well water) outcoming is 0.

 

[3mm3]

ok, so maybe back way off on the nopox? i went to carbon dosing after a gigantic hair algae problem, but that problem has since been completely cleaned out.

I would back way off carbon dosing. I was running nutrients that low and wiped out my entire sps collection about a year ago. I went back to old ways of the basics and everything is growing crazy fast now.

 

[Klatt]

ok, thanks for letting me pick your brains! ill stop the nopox and monitor nitrates and point of sale, see what happens.

 

[3mm3]

The recovery will be slow but should definitely notice coral health improve.
Do you have any monti cap still hanging on? I use those for my canary coral.

 

[Klatt]

nope, lost the caps completely. i did buy a new one two months ago when i thought i had things going back to normal, but it died within two weeks.

 

[sfin52]

Seachem makes a good phosphate that you could dose slowly to get phos up.

Do use over feeding to bring up nutrients. It will cause more harm than good. You also can’t measure it or control it.

 

[wopadobop]

Sea chem phosphorus
Spectracide stump remover granules for nitrates.
Get po4 to 0.05 at minimum and get nitrates to around 3 ppm minimum.

Here’s the trick. Dose the nutrients to those levels. Then feed regularly and adjust only the nitrates to control po4.
You’ll find that the system will begin to consume po4 and nitrates all on its own. Feeding will replace the po4 and dosing the nitrates will help consume them. I have never done any one thing so beneficial for my tank than adding nutrients back into the system.

You’ll see immediate improvement and colors will start to pop after a bout a week,

Keep us posted.

 

[2Wheelsonly]

ok, so maybe back way off on the nopox? i went to carbon dosing after a gigantic hair algae problem, but that problem has since been completely cleaned out.

Was your hair algae problem due the tank being new and your rocks possibly leaching po4? I'd ditch the nopox completely and let your nutrients raise a bit to feed your corals. I keep my nitrates around 10 and my phosphates at 0.06 and it's hard to find any algae other than having to clean the glass every 3-4 days.

 

[Klatt]

Was your hair algae problem due the tank being new and your rocks possibly leaching po4?

I think that was the issue, the tank was about 6 mos old.

I just turned off my GFO reactor too.

 

[2Wheelsonly]

I was stubborn, took me forever to realize I needed to get rid of GFO and carbon dosing; once I did my tank did a 100% turn around.

Now I’m fighting lighting and alk stability. It’s always something!

 

[Klatt]

did you also dose nutrients, or just stop gfo and carbon?

 

[dvbrien]

You guys that are adding nutrients back in... and have stopped gfo, have you stopped using activated carbon too?

 

[sfin52]

No I’ve not stoped AC. keep the activated carbon going. I did stop gfo.

 

[Tahoe61]

What types of corals?
What percentage of water are you changing out and how often?

 

[2Wheelsonly]

You guys that are adding nutrients back in... and have stopped gfo, have you stopped using activated carbon too?

I did, but only at the advice of a very well respected fish store. I honestly wish I could provide more reason to remove it but when I run into big problems I try to simplify and remove all unknown variables. Other than my water slightly less clear (I have a diamond goby that loves to eat and will never have clear water) I have not noticed any issues. I had some LPS die off but my ability to keep hammers, and torches is very limited I think my flow rips them apart.