No idea how to fix what is wrong with my tank?!

[Gwitness]

I have a 180 gallon mixed reef and I have about 15 SPS and then a bunch of LPS corals.....NONE of my corals seem to ever grow (including LPS) and most of my SPS end up starting fine and then some will slowly turn from white at the end of tips and grow algae on them and just slowly start to go down on the coral, and then some are fine like my red planted and oregon tort!! This has been going on for a couple months now....I try to keep my parameters as stable as possible and here is what I run and where my parameters are at now....

I run:
UV sterilizer
ASM G4+ skimmer
Dosers for alk and ca
manually dose Mg
BRS carbon and GFO reactor ( started about 2 weeks ago)
Radion Pro Gen 3 lights with 2 t5 strips (radions max out at 45%)
FLOW= mp40 and then a jebao rw15 and a jebao rw20...(confused why algae and cyano will still grow on rocks and corals when the flow is strong?)
I use a spectra pure unit for RO/DI and I do a 15 gallon water change every week using aqua vitro salinity salt


Parameters:
Nitrate 10-15 (salifert)
phosphates: read 0 on my hannah checker every time I check but no idea if that is right or not because I have algae on rocks and back of tank
CA is 420 (salifert)
MG is 1250 (salifert)
ALK is 8.0-8.5 (Hannah)
PH- No Idea

my CA is always stable and check once a week
my alk I check about every 3 days and might vary .3 0r .4 over 3 days or so
MG is always above 1200-1300

I just treated tank today with chemi clean for cyano also.....Any help or advice would be awesome because I honestly don't know what else it could be! Thanks in advance!

 

[Randy Holmes-Farley]

I'm not sure what the issue is.

Which Hannah checker for phosphate?

 

[Gwitness]

I use the phosphate low range one...thanks for trying to help out randy

 

[luke33]

How old is your tank and what kind of rock did you use in it?

 

[dbrewsky]

how much GFO are you running? I had a similar problem where my tank was simply too new and running aggressive gfo/carbon and skimming literally stripped the water too clean. I also increased my light intensity quite a bit since I was super worried that my Kessil 360we was going to be too strong. I haven't had active gfo in my aquarium for over a month and have noticed some growth and colors coming back without an increase in algae.

My vote is cut the gfo, keep a reasonable amount of carbon running and change it consistently and keep up with the water changes to drop your nitrate a bit.

I would also consider ramping up your lights slowly, but i dont have radions, so hopefully someone can chime in.

 

[Randy Holmes-Farley]

Yes, that was my reason to ask about the checker. You might be starving the corals, and less agrees dive GFO might be worth a try.

Did you have this issue before any GFO use?

 

[Gwitness]

Tank has been running over 2 in a half years and rock is some of the man made reef rock mixed with Fiji rock.....this issue was going on awhile before the gfo and carbon reactor and that is one of the main reason I got it....I have algae growing in the tank so it's not super low where no algae is growing on glass or rocks/back of tank....I use 1 cup of carbon and 1 cup of gfo

 

[Gwitness]

Could my nitrates or phosphates be way higher than what they are reading?? If so how can I know that

 

[reefer_madness_01]

Following...
I have almost the exact same issue and setup

 

[reefer_madness_01]

My tank is mixed reef 150 with 2 radions, skimmer, BRS 2 part dosing pumps, 2 MP40s, mixed man made and natural rock.
It is about 3 years old. For the first year or so everything was growing great, healthy and had almost no livestock loss. Over the past year or so, results have been mixed with some coral still doing great (zoas/palys, pocillopora, pink birdsnest, duncan, miami hurricane) while others have not done well (lost a big ORA birdsnest, RTN in a red monti, total bleaching of a green monti, blue, green and red digitata with periodic bleaching, toadstool with retracted polyps for months now, same with a pink goniopora). I had a cyano break out a few months ago that did not respond to CUC revamp, chemiclean, 48 hour lights out etc so I added phosban and carbon reactors. Algae has melted away with phosban but coral looks worse if anything.
I had some mild alk swings but overall things have been pretty stable
calcium 420-450
alk 8-9
ph 8-8.3
phosphate 0.0 on low range checker (it was 0.0 when I had cyano outbreak also)
My maintenance schedule is 15 gallon water change weekly with sand vacuuming. I feed LRS frozen food daily (a chunk about 1 inch square) and try to feed a 2 inch square of dried seaweed. I have 8 fish (3 tangs, 2 clown, six line wrasse, coris wrasse, coral beauty angel, neon dottyback)

I'll probably post my own separate post but I thought I would add it here also for reference

 

[dbrewsky]

You could be using too much gfo trying to reduce nutrients too fast stripping the water. You can still have algae which has already locked up nutrients that the gfo will not remove. Usually algae management is best controlled over the long term with consistent water changes and low to moderate use of gfo. You must remember that your corals algae crop needs the same nutrients as the algae you are fighting.

Also phosphate is only one of the macro elements that algae needs to grow, reducing your nitrates through water changes will assist. I would recommend cutting your gfo use down and ensure you change it consistently. I have noticed in my tank of 100 gal volume that 2tbs of gfo will strip .04 phosphates practically overnight!

Out of curiosity are you using ro/do and testing for tds in your product water?

 

[reefer_madness_01]

I have my own spectrapure ro/di and tds is 0
My problem with algae seemed to be that no matter what I did I couldn't get rid of it (water changes, aggressive vacuuming, rock basting, nutrient export mode on mp40s, etc) and only thing that worked was gfo. Is it a matter of finding the "sweet spot" with my gfo so that algae is reduced and coral can grow? That seems like a tough task...
it is frustrating to see people's tanks that look completely awesome and they are like " I don't do much....just water change every couple of weeks" while I spend all kinds if time, energy and money having to fine tune every detail of my tank...ugh

 

[Gwitness]

Amen.....like you said I'm in the same boat and still no idea

 

[Randy Holmes-Farley]

Could my nitrates or phosphates be way higher than what they are reading?? If so how can I know that

I don't see any reason to think the tests are inaccurate, but you cannot know for sure without confirming with another kit.

 

[Gwitness]

Okay thanks...Just did a 20% water change after my chemi clean treatment and phosphates finally didn't read 0 and actually read 0.03 so hopefully time will tell and not do any changes unless needed