Tank Reboot & How to fix GHA problem

[taulgrl]

I’m weeks away from moving my current 5 yr mixed reef to a new Waterbox 110Ex system. New tank and sump are about the same size as current tank (80 gal)

I have been battling uncontrollable GHA growth in my current tank for almost a year and nothing seems to be working. Parameters in line with recs and stable (Alk 8.5, Nitrate 5-10, Phos 0.03). Running GFO, carbon, and dose Kalk. I replaced all RODI cartridges and membrane, have ~30 snails, 2-3 urchins (big and old tuxedo just died), a few hermits and just got a sea hare (who doesn’t seem overly hungry). Algae eating fish = Scopas tang. Maintenance = manual GHA removal w 10-20% water change every week or two. It just grows back like crazy!

So, I’m giving up and hoping that moving to new tank will help. All equipment will be new. My plan: I’m starting w new live sand but I hate to start over w new rock. My plan is to scrub the heck out of them and rinse in fresh RODI before transferring.

What suggestions to people have? I’m wondering if I should throw my UV sterilizer in to see if it helps at all… only thing I can think of other than adding algae killing chemicals (don’t want to do that)

 

[Privateye]

Good luck!

Personally I would scrub the rocks and rinse with tank water. That way your beneficial bacteria won't be impacted, and you won't have to worry about any die-off polluting the new water. You'll probably want to give them a good shake in the water too. They're likely full of detritus by now.

I'd add the UV, especially since you've retained a lot of your beneficial bacteria from scrubbing the rocks in tank water. I'd run a protein skimmer too if you have one.

 

[exnisstech]

Adding some or all live rock would be the first thing I would do. If you scrub the the existing rock (which I understand and don't disagree with) and rinse it in RODI its going to be very similar to starting over with dead rock and the same rock that's already proven to grow algae. Did you start with dry rock the first time? I know many succeed with dry rock start ups but when I did it my tank was a mess for over a year untill a seam failed and I broke the tank down. If I use dry rock in a display now I pack the sump full of as much live rock as I can fit and I've pretty much avoided any uglies. I don't know what causes it but I've had some rock get covered in GHA and the rocks around it remain algae free.

 

[Biokabe]

GHA is complicated, but not overly so. It's almost always a combination of three factors:

First, overloading nutrients into your rocks. The waterborne nutrient number is irrelevant here - GHA is a huge nutrient sink, so it's very common to have a tank with an overgrown GHA and low or non-existent testable nutrients. Detritus settles in on your rocks and serves as in in-situ source for algae growth.

Second, inadequate consumers. Algae is everywhere. It's always going to pop up. So you need things that will eat it when it does pop up. But, once algae gets too long, your critters become disinterested in it. Too hard to eat, doesn't taste good - I'm not an algae eater, I don't know why they don't like it. I just know that they don't. So once it gets really long, your algae consumers will skip over it in favor of other sources. But on top of that, it's not just algae consumers you need. You also need scavengers that will eat the same detritus that feeds your algae.

Third, inadequate export. A protein skimmer, refugium, or algae turf scrubber can all help here. They provide an easy way to pull things out of your water and tank without having to directly interact with the inside of the tank. Skimmer works to pull nutrients out of the water before it can fuel algae growth, refugium and algae scrubber both provide an idealized algae growth site that can outcompete in-tank algae (especially since they're not getting eaten by your CUC).

As for what I would recommend for you:

First, clean detritus off of your rocks. Blowing it off with a turkey baster or similar can work, but I actually found the Hygger aquarium brush to be really useful here. It's a waterproof powered brush with a few interchangeable heads, and I found that it honestly works really well to liberate detritus from your rocks and detach algae holdfasts from your rocks. It's definitely tricky to work around corals and I wouldn't risk it if your rocks are covered with mounted coral frags. But if you have any large expanses of rockwork that don't have corals growing on them, it can make a huge difference.

Second, add a second algae-eating fish. A one-spot foxface is a decent match for your tank size and it's one of the few critters I've seen that will occasionally attack the longer algae strands. Between that and your tang, they should keep your rocks mowed once you can get the forest cut down.

Third, if you don't already have them, add a protein skimmer and an algae turf scrubber. Both are relatively expensive so I won't say you absolutely need to do that. With that said, though, either of those would be more useful (specifically for dealing with GHA) than a UV sterilizer.

Fourth - add to your CUC. Bring in some detritus specialists (hermits, nassarius, etc). Conches can also be good here. If you don't already have any, zebra turbos are awesome algae eaters. Treat them like urchins, in that they can absolutely bulldoze frags off of your rocks, but the difference is that they'll just knock them over instead of carrying them off like a trophy.

 

[taulgrl]

Adding some or all live rock would be the first thing I would do. If you scrub the the existing rock (which I understand and don't disagree with) and rinse it in RODI its going to be very similar to starting over with dead rock and the same rock that's already proven to grow algae. Did you start with dry rock the first time? I know many succeed with dry rock start ups but when I did it my tank was a mess for over a year untill a seam failed and I broke the tank down. If I use dry rock in a display now I pack the sump full of as much live rock as I can fit and I've pretty much avoided any uglies. I don't know what causes it but I've had some rock get covered in GHA and the rocks around it remaining