Cyano hurting coral (pics)?

leevh

New member
Hello, I'm hoping for experienced advice on my situation. :)

Pics:
https://goo.gl/photos/eRojPFfTZYJQ3Lz86

Problem: soft coral (star polyp, pulsing xenia, kenya tree) are not full extending anymore and appear to be suffering. Sand keeps turning brown/red with what I believe is cyano within only a week of a 20% water change. Water changes temporarily improve look of coral each time.

Tank: 75 gallon corner, 4 years old,
flow is 2500 GPH mostly from one powerhead.
Skimmer is bubble magus curve A5
light is one AI Hydra 26hd led unit, planning to get another when I can afford. On 6 hours a day
Open top (no lid)
NO auto top off, so skimmer often not running at most efficient
NO reactors or anything, just carbon and RowaPhos in sump and filter pads

7 fish, feeding small amount of nori daily and 1/2 to 1 cube of spirulina frozen brine shrimp and pellets once in a while for variety

Cleaners: Down to about 5 snails (haven't bought more in about a year), two tiger tail cucumbers (1 that split into 2) I know this is really low..

Water: Use RODI, 20% water changes every two weeks lately to combat problem. Temp hovers around 26C (78.8f), salinity 1.025. From my nutrafin chemical test kit, the only parameter that stands out is minimal phosphate ~.25mg/L. Every other test I have is "optimal"

Other possibly useful info:
When we inherited the tank 4 years ago it had a BAD hair algae problem. We fought it for 3 years and made progress and last year decided to flip all the rocks - This worked, no hair algae since. I suspect though the rocks may still be leaching something. When we got the new LED light 9 months ago, all coral was happy and reacted very well to it for many months. We've also been fighting the brown/red stuff to some extent since as long as I can remember, but it seems to be getting worse now. The effect on the coral has only been for about 2 months and seemed to come out of nowhere as nothing had changed for about 7 months before that. I've started sucking up the red stuff off the sand which comes up in carpety chunks. In about a week full sand bed is mostly red. The pics below are about 4 days since last water change.

I'm by no means good at this, just slowly improving over the years so any advice helps. I'm considering at this point:
- more snails
- more flow (another powerhead)
- auto top off (keep skimmer working better)
- UV filter (possibly kill cyano?)
- replacing sand bed with new clean sand
- another LED Hydra light (hopefully help corals not stretch so much)

thoughts? thank you so much for reading :spin1:
 
Corals look fine in the pictures..
But you should do a water change and siphon as much of the cyano out as you can then turn off the lights for 3 days.. Then do another water change and siphon out whats left of the cyano..
Then repeat every couple weeks as needed..
Start there and see how it goes..

More flow certainly wouldn't hurt either.. You are right around the minimum I would recommend in any tank.. Another 1000GPH or so would be good..

IMO 8 hours of light is better than only 6..

phosphate levels indicate you might be over feeding some..
Reduce food slightly too..
 
Thank you mcgyvr, they do look ok in the pics, but previous to this last couple months they were much more extended and flowy. The green on the star polyps is only millimetres extended rather than looking like short grass like it should :( The xenia used to be big poofs of white rather than tiny ones on top of the long stalks.

Great advice though, I've upped the photoperiod to 8 hours and will reduce food a bit and keep on siphoning!
 
Just a question, do you get much daylight where the tank is at currently? The few times I had it in the past it seemed to correlate with longer daylight hours on top of what mcgyvr said which is spot on advice.

Most algae and cyano problems can be helped along with simple removal, bubble algae too.
It's a fairly easy fix just an occasional persistent problem :).
 
You got the tank 4 years ago & kept all the sand, live rock etc? If so, I think the sand is the cause of the algae blooms. Sand beds are great IMO , but I only ever take a few handfuls from an old sand bed to use in a new tank ( moving to a larger tank, moving house etc ). The sand is great at locking up pollutants, but can be a nightmare when disturbed & all those locked up nutrients are released over time.
I would seriously consider trying to siphon out ( or remove by hand) as much of the old sand as possible. You can break the tank down into sections if you want, but I would just go for removing as much as possible in a single day & add the new sand.
 
sh4rkbyt3, Our tank gets a lot of daylight, mostly not direct sunlight (but occasionally) because its upstairs in our living room where its bright. Currently it gets daylight from dawn to 2pm, then LED from 2pm to 10pm. Dark blue light from 10-11 and dark from 11 to dawn. I've often wondered about the effects of all the daylight, the fish are up and awake during that time and the corals partly too. We just like the tank lights on in the evenings when we're actually home to enjoy them :) Could this be a problem?

45commando, We did keep everything including the sand. Though I think from the siphoning over the years we've probably replaced 3/4 of it already. A good idea though, I've been thinking about replacing it. I've wondered how much PO4 was locked up in those live rocks too.. perhaps I should look into cooking them.

Thanks you both, I really appreciate the opinions!
 
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