34 gallon frag tank doing horribly

[AtlCPA]

I'm not totally new to the hobby, but this is the first time I've tried to run a small frag tank and it's going horribly. Started the tank and had it cycled in October.

I've had larger tanks and they've done just fine. Coral showed growth, didn't lose color, etc.

This frag tank I have is 34 gallon, bare bottom, some live rock in a 20 gallon sump with reef octo skimmer. Maybe 45-50 gallons of total water volume.

I have two Kessil lights that I ran on my 75 gallon before and the coral were fine. I've also added a 24" T5 fixture that I'm running about 3hrs a day and the LED's about 8 hrs a day.

I test the water religiously with red sea kits. I test alk, ph, salt, mag, calc, etc. Has been stable there other than one alk spike that killed a few corals and maybe has linger effects two months later.

I just stopped dosing anything after that, did major water changes, etc. Also phos got a little high, browned some corals within the fist two months so I picked up water changes to weekly.

I've lost probably 7-8 corals, a torch currently dieing, a 6inch wide Jedi Mindtrick I have looks like crap, etc.

Is it the bare bottom or not enough live rock? I probably only have 7-8 pounds of live rock. I've tried a lot with the water quality and nothing seems to be helping. I'm starting to think it has to do with the live rock and no sand.

 

[saltyfilmfolks]

What exactly is the symptoms of the coral?

Do you have a par meter?
Lux meter?

 

[Bdrake]

Can you post your most recent measurements and possibly pictures?

 

[AtlCPA]

I may have just figured it out. I have been dosing Vibrant which I've used in other tanks in the past.

I've been using the Saltwater version vs the reef version. I never realize there were two versions. The bottle doesn't say anything about for fish only tanks, but when I look on their website, it does say fish only tanks or get the reef blend for reef tanks. https://www.uwcmn.com/product-page/8oz-vibrant-for-saltwater-aquariums

Anyone have experience with this?

 

[AtlCPA]

parameters are:

.022 salinity - lower than I thought after I recalibrated my refractometer. Maybe that's the issue.
.03ppm Po4
8.2ph
8.5 alk
390 calc
1150 mag

 

[Bdrake]

Cal and Mag are both pretty low as well and slowly adjusting those back up should be included in your plan of action. Bare bottom won't be an issue but 8 pounds of LR in a 34 may not be enough rock to sustain itself biologically. Do you have any other form of biological media (MarinePure, Biopellets, etc.)? Nitrate and ammonia readings would be helpful as well.