Tank is crashing :(
 

Hey guys, maybe someone here can help my figure out this crash. My tank is going through a crash right now. All the fish are fine but I'm losing all my corals (sps and lps). I've a ready lost some large sps colonies and at least a dozen smaller ones and a bunch of frags. My sps started bleaching some from the top, others from the bottom and others from the middle. My lps aren't many (mostly acans) half have died and the others look fine. My Monti caps are even getting random bleaching spots.

I have always used t5 since the beginning of this tank but in January I switched to led to get away from the hassle of changing bulbs. Everything looked great or about a month and then the sps started receding where it was being shadowed. And getting random burn spots. I figured it was the fixture not being full spectrum and not enough spread so 2 weeks and I got rid of that fixture and replaced it new ones that are full spectrum and will cover the tank more so I don't get any shadowing and also added some t5. Things kept going downhill and dying.

300 gallon tank actual water volume
Alk 8
Cal 470
Mag 1320
Po4 0.04
Nitrates undetectable
Potassium 390
Sg 1.025

I've also replaced the cal, mag, and alk kits to confirm my readings.

I was using a doser for years and worked well but I switched to a calcium reactor in January to make things a little easier. At that time I had the parameters dialed in 8 alk 420 cal and 1350 mag. Tested for a couple weeks and held stable so I only tested alk from that point. I tested last week and alk was 8.7 but cal was 490 and mag was 1320. I'm back to dosing to bring the calcium back down before I turn the reactor back on. I just tested at 470 right now.

I've replaced carbon and gfo often, keep filter socks clean and do all the maintenance to keep it clean and nothing changes.

All I can think of is that in January I bought some nori for my tangs from Walmart. I used it for about a week but I didn't like it because it would almost fall apart in the water. I then looked up the ingredients online and there was some oils that they added to it so I went back to feeding my old nori. It almost seems like my skimmer hasn't worked right since then.

Also around January my rodi filters got neglected and the d/I was exhausted. I'm not sure for how long but I'm sure some stuff got through the filters. I've replaced everything since then.

I've also checked for stray voltage and didn't get any.

Only thing I haven't done is a water change due to the large volume of water needed to make a difference.

Any ideas guy?

Hey man that really sucks

But from what from I'm reading if your fish are ok and it started with corals and your parameters have been stable the only other thing you Changed that was big was the lights, LEDs are a big change from the T5 specially if you haven't been up on changing the bulbs you could have had a massive par swing from like 300- over 1000 some lights are depending what u got and settings and height , i would start there dial back the lights % if you can or shorten the time they are on

Seems your water is good but with death water changes are never a bad thing maybe try doing a few decent % WCs to see if you can turn the tide

Hope that helps man not sure

Do you do regular small water changes? I just went through a mini crash (tips burning, some coral expelling all polyps) and it turned out my source water was high on chlorine because my RO filter couldn't handle it and it was passing through.

If you don't do changes do you replenish the trace elements?

It could be a lot of things, can you post a picture of the tank and some examples of whats going on?

Sorry to hear, iceman86.
A few questions:
Did you measure the PH before and after the addition of the calcium reactor?
Do you have a sandbed?
What light fixtures were you using and which ones are you now using?
What do you have for water circulation?
How much GFO have you been using and how often are you replenishing it?
How long has the tank in it's present state been running for?
Can you post a link to the Walmart nori?

Please post a picture as mentioned above.
I'm not a fan of GFO because it will remove trace elements, so I would recommend a larger (25%) water change sooner than later.

Can we get some pics of the tank before and after....maybe some close ups?

Thanks for your help. I changed to led when the t5 where about 9 months old so I can be shock as you mention. If I can't seem to figure it out, I'll do some large water changes to remove anything that may be in the water.

I hand done a water change in a few months but I do go through a lot of top off water due to evaporation. I was dosing trace elements from aquaforest and didnt have any issues but then I stopped when things started dying.

I'll try to get some pics up for you guys to see

My ph before the reactor is 8.3 and with the reactor it did with it it's about 8.2 and would drop to 8-8.1at night.
I also have a ph probe right in the reactor as well measuring a oh of 6.7
Yes I do have a coarse sandbed.
At first I switched from 2 tek t5 fixtures 8 bulb each to 2 vertex illumina fixtures. My latest set are 5 mars aqua fixtures along with 4 36" t5 bulbs.
For water circulation I have 2 maxpect gyres that will blow the sand around if not turned down.
I run 1000 of gfo and that lasts me about 2-3 months. I have 7 tangs who poop a lot lol
This tank itself has been running for about a year but the live stock has been with me for about 5 years while upgrading tanks .
I tried looking earlier on the Walmart page for a pic of the nori but I couldn't find that exact one sorry.

It's been a while since I posted a pic. Can anyone give me some instructions ?

Just upload to photobucket and copy and past the img tag