Nutrient issues long term.

[barjam]

About a year and a half ago I upgraded my 90 gallon tank to a 120 (both BB). At some point prior to that I switched from kalk to 2 part. Bio load wise it is roughly the same. Equipment is also the same other than an upgrade from hellolights de reflectors to lumenbright de reflectors 16 inches off the water measured from the bulb. Photoperiod is 6 hours. Skimmer is an msx-160.

Ever since the upgrade I have fought brown hair algae with an occasional smattering of green ha. They are identical other than color. I have combated this with GFO and vinegar dosing. It isn't plague proportions or anything just annoying. It is also constrained to certain rocks (most of them but not all) and doesn't seem to spread.

Nitrates/phosphates are always zero (salifert/Hanna). Sps corals are exceedingly pale and other than a washed out green slimmer, green birdsnest and bird of paradise are very, very slow growing.

The tank is clean. Detritus is siphoned. Sump is empty. Rocks are scrubbed when I can get to it. The tank used to be gorgeous and my husbandry hasn't changed.

The glass is pristine. I wipe white dust from the vinegar dosing off the front panel once a week. I haven't wiped the side panels down in months as they don't need it. There isn't a hint if green and in the past year zero coraline has grown on the glass. It isn't a light issue as it grows on the overflow and powerheads just fine. It grows very well under the rocks and grows so-so on the top of the rocks without algae.

So my thoughts are the rocks are just leaching phosphates. Hence no algae on the glass and my only real option is to wait it out. It is getting better just very, very slowly.

Any other opinions? If it was tour tank what would you do next?

 

[DNA]

Since you have some algae I'd run the usual remedies to reduce nutrients.
Are you sure the brown algae is not dinoflaggelates?

 

[barjam]

Since you have some algae I'd run the usual remedies to reduce nutrients.
Are you sure the brown algae is not dinoflaggelates?

Thanks for taking the time to respond, I appreciate it.

Yes it is not dinoflaggetes it is the exact same structure as hair algae and has no bubbles. There are a few species of brown/red cyano that sort of look like hair algae maybe they are related.

The path I was taking with heavy carbon dosing keeping nutrients low was failing me. The sps were so starved they were basically bleached. Or it is possible it was too much vinegar (.5 ml / gallon).

In any case I am taking a new path and concentrating on coral health. Once the corals are healthy again I will reevaluate. I know it is counterintuitive that I should feed a tank with algae more to help the corals but I found out by accident that heavily feeding the tank causes the sps corals to color up nearly overnight. The coraline also became a tiny bit more saturated color which I did not expect nor have I ever heard of happening.

The plan:

1) Stopped carbon dosing
2) Feed more to get the corals healthy again
3) Led lit fuge with macro algae
4) added 10 turbos and two urchins
5) continue gfo to keep phosphate at .02 or lower

I have noticed where the long spined urchin cleans nothing but coralline comes back. So that is progress.

 

[DNA]

Your plan steps 3, 4 and 5 look good to me, but I'd skip 1 and 2.

Phosphates are bad for coral growth and your plans to stop carbon dozing and to feed the tank more will increase your phosphates and fuel the algae. I'd make it my priority to get the macro algae in the display tank and PO4 under control.

Are your corals receiving enough light?
Now you have a larger tank, but still using the same bulbs as before.
Our eyes are no good at judging light intensity, old bulbs, murky water or no carbon will reduce it.
New bulbs if they are getting old and perhaps an hour or two longer photo period seem like a good idea.

I take it your parameters are perfect.
I've had a faulty test kits twice so double check at the LFS or with a friend.

The way you stacked the rocks in your old tank would let a lot of detritus accumulate under them.
Is there good flow throughout the current tank?

 

[sirreal63]

Where did the rock come from?

 

[barjam]

Your plan steps 3, 4 and 5 look good to me, but I'd skip 1 and 2.

Phosphates are bad for coral growth and your plans to stop carbon dozing and to feed the tank more will increase your phosphates and fuel the algae. I'd make it my priority to get the macro algae in the display tank and PO4 under control.

Are your corals receiving enough light?
Now you have a larger tank, but still using the same bulbs as before.
Our eyes are no good at judging light intensity, old bulbs, murky water or no carbon will reduce it.
New bulbs if they are getting old and perhaps an hour or two longer photo period seem like a good idea.

As far as carbon dosing I think maybe at least reducing it be in order. I dose 50ml into the tank. It doesn't seem to do anything and the corals look much worse since upping the dose a few months back. Very pale.

I take it your parameters are perfect.
I've had a faulty test kits twice so double check at the LFS or with a friend.

The way you stacked the rocks in your old tank would let a lot of detritus accumulate under them.
Is there good flow throughout the current tank?

Light is 2x250 Phoenix 14k lumenbright reflectors 16 inches off the water surface. The bulbs are about 4 months old or so. Photoperiod is 8 hours. Coral distance to light between the 90/120 is about the same probably on average 2-3 inches lower.

Phosphates are measured with the Hanna hi-736. Gfo is changed when phosphates raise above .02. Phosphates register zero on API and salifert as well.

Nitrates measure zero on salifert and API.

No algae of any sort grows on the glass, overflows or powerheads. It also doesn't grow on certain rocks. I haven't wiped down the side/back glass in 6 months and they are clear. I wipe down the front glass every other week to remove the white carbon dosing dusting.

 

[barjam]

Where did the rock come from?

Same rocks I have had going on 8 years. Early on I had sand and they definitely got gunked up then although I really didn't have algae problems and didn't really have them when I went BB in that tank.

I kind of think maybe stopping kalk on top of rocks that were in a phosphate loaded tank for so long might be the issue but who knows.

It seems as my husbandry has gotten much better on paper the tank has actually gotten much worse.

 

[sirreal63]

It is possible that some of the rock has some bound po4 that is acting like a fertilized bed for the algae, it is usually found on terrestrial based rock like Marco or BRS Pukani. There are a few solutions like lanthanum chloride and an acid bath, or of course replacing the affected rock.

 

[Palting]

Time is your best weapon. Let the refugium mature, it will consume the nitrates and whatever phosphates the rocks may be leaching. I happen to agree with all your plan. You can also add a herbivore, like a kole tang or risk an angel, to eat the GHA. Although my refugium contains GHA as well as the macro, no GHA can grow in the DT due to my tangs and the CB angel. The brown furry turf algae I used to have is now all gone, thanks to two black long spine urchins. Between the tangs and the urchins, I believe you will have better success than with the turbos. You have to keep making sure those things stay upright, anyway, so I think they are more of a bother.

HTH!!

 

[barjam]

I have a kole, Yt and a flame angel. The YT would rather go around with a pinched belly rather than eat the algae. Flame seems to pick at it. Kole is only interested in glass. They are all relatively young though.

Here is my stock list and skimmer maybe I am overstocked:

1 yellow tang
1 kole tang
1 flame angel
2 clowns (false percs)
1 royal gramma
2 lyretail anthias.

Skimmer: msx 160 with red devil pinwheel.

On average I feed a pinch of flake a day. A couple of times a week they get a cube of frozen mysis. Rarely I throw in some algae. Once a week at most.

On the 90 I had macro but it never grew so I ditched it at some point. Maybe it was just enough to tip the balance who knows.

 

[barjam]

Per what DNA suggested I am keeping the feedings light and dosing 37ml of vinegar a day.

 

[sirreal63]

You can certainly do that, it is what you have been doing, but I don't think it will help with the pale corals. While it is true the no3 and po4 in the wild is very low, there is also a tremendous amount of food available, and you do not have that available for your corals. The lack of algae on the glass is a clue that your tank is too clean. The zooxanthellae in the corals needs a nutrient source or they too starve. I wouldn't wait too long before feeding the tank more, if you follow your plan another month and nothing improves, I would be adding some nutrients to the tank. As far as the algae on a few rocks, they can consume the po4 from the rock surface and grow, even if the rest of the tank is nutrient poor.

 

[DNA]

I see macro algae as a positive thing as long as it's out of sight.
It's what they consume that I don't like.

I read 6 hours in the first post so I suggested a slightly longer photo period.
Some pictures and more info on your tank would help if you like more help from fellow reefers.