Low Nutrients, lots o' Algae

DrBoxedWine

New member
My 75g tank with 30g sump has gotten quite the algae growth lately. It's kinda tougher stuff, almost "tufts" in some places. A little hair algae as well, but not too bad. I have a fuge that keeps nitrates undetectable, and I started running GFO maybe 6 weeks ago. Phosphates test in the 0.02 range. I have 2 Hydras running maybe a bit more than usual, but nothing too crazy. I do have the greens and reds turned up to about 40%, and i'm wondering if i should turn those down?

Anyway, last night the Mrs and I got some toothbrushes and went to work. Ripped it off where we could, and then got to scrubbing. I started the tank back in August, but ran Hypo between mid-dec through mid-feb. This definitely set the tank back a bit, and i've gotten some of the early tank nasties again. I used to have a foxface (had to rehome him as he grew a taste for zooas) that ate any sort of algae and that may have been why i didn't notice this before.

I do feed a bit, but not crazy. I have 2 clowns, a flame hawk, bicolor blenny, melenarus wrasse, kole tang. All the food is gone within 30 seconds to a minute when i feed once a day. I also Skim heavy. I don't THINK excess nutrients should be my problem.

Is this just a thing that i have to let run it's course?
 
Personally it took my tank a while to get rid of the tufts of GHA, even after adding a lawnmower blenny and GFO reactor. It seems to have a handle on it now but I did have to manually remove a lot along with the other preventions added. Now between the blenny and GFO, it's down to a manageable "fuzz" that feeds the blenny and keeps him happy.
 
My Lawn Mower Blenny is the laziest blenny you've ever seen. He doesn't bother with the GHA anymore. He waits for the flake to drop in and eats that. I still love the little guy though ;)
 
How long has your tank been up and running and did you dry rock. If so, it's possible that they can be leaching phosphates out into the water. It's my understanding, if you have algae that you are not going to have a true reading due to the algae soaking it all up. So technically you might have alot of nirates and phosphates going on. For as the blenny, I would skip out on, once the algae is gone so is the blenny's food source. I would start GFO with half the dosage and gradually work your way up to full dosage.
 
if you want to see if the rock is leaching, remove a peice of the rock and drop it into a bucket of just RODI water. wait a day or so and then test the bucket water for phosphates. i am going to guess its going to be a lot more than .02 :D
 
I started the tank back in August, and i used BRS Reef Saver Rock. This algae is sort of a newish thing. It was pretty clean for a while, but i'm realized my foxface may have had something to do with that. I'm wondering if maybe a few Trocheus snails would help.

I've been running a full dose of GFO for about 6 weeks now. I actually just changed it out last week. Phosphates started out high, so the first batch didn't last all that long.
 
You may need to change the gfo more often. You may have a nutrient source you're not thinking of, like detritus or dirty filter socks or something. Probably more of a thing to actively manage vs let it run its course, although it can take a while to resolve. It might feel like you're just waiting it out. [emoji1]
 
You may need to change the gfo more often. You may have a nutrient source you're not thinking of, like detritus or dirty filter socks or something. Probably more of a thing to actively manage vs let it run its course, although it can take a while to resolve. It might feel like you're just waiting it out. [emoji1]
Thanks. Yeah I gave the sump a good cleaning the other day, hopefully that helps. Maybe it's time I take a turkey baster to the rocks, as well.
 
i would agree. if you have algae problem then there has to be nutrients coming from somewhere. step up your gfo a little, maybe cut back your feeding a little, plus what are you feeding them. you say its all gone in 30 seconds, maybe feed that amount over 4 times. also if its frozen cubes are draining the dirty water out. yes blast your rocks once in a while cant hurt. also blast your corners or dead spots where the flow isn't that strong. keep changing that filter sock often. make sure detritus doesn't build up in your sump. maybe get a few more cuc. all things to try that cant hurt right. but remember your eyes see algae so they are feeding on something in your water. also not sure how long your lights are on or what intensity, but maybe cut them down all things to think about. so many factors go into a reef tank, its hard to really pick one thing out without seeing your tank. goodluck
 
My Lawn Mower Blenny is the laziest blenny you've ever seen. He doesn't bother with the GHA anymore. He waits for the flake to drop in and eats that. I still love the little guy though ;)

I haven't spoiled him yet with flakes or shrimp. Eventually I will supplement his diet but right now he's still trucking along with the algae.

i would agree. if you have algae problem then there has to be nutrients coming from somewhere. step up your gfo a little, maybe cut back your feeding a little, plus what are you feeding them. you say its all gone in 30 seconds, maybe feed that amount over 4 times. also if its frozen cubes are draining the dirty water out. yes blast your rocks once in a while cant hurt. also blast your corners or dead spots where the flow isn't that strong. keep changing that filter sock often. make sure detritus doesn't build up in your sump. maybe get a few more cuc. all things to try that cant hurt right. but remember your eyes see algae so they are feeding on something in your water. also not sure how long your lights are on or what intensity, but maybe cut them down all things to think about. so many factors go into a reef tank, its hard to really pick one thing out without seeing your tank. goodluck

:uhoh3: Your post makes my head spin buddy! lol
 
Green algae depends on ONE principal nutrient: phosphate, which comes in rocks and tapwater, mainly. Algae IS a phosphate test. Your box test can say zero, and the algae will say, yep, you have it, because it's bound up in the algae as it soaks out of the rock. Probably the tufts are right where it's soaking out.
 
Are you running LEDs? If so, turn your whites off or down to like 10%.

I had the same problem, thick green algae everywhere. I scrubbed the rocks off with a toothbrush and turned the lights off for three days to help kill the algae. When I turned the lights back on, I excluded the whites. This killed all the algae from my rocks, and I tried everything like you have. PO4 was not my problem. You don't want to strip your water too much, the corals won't have the nutrients they need.
 
Green algae depends on ONE principal nutrient: phosphate, which comes in rocks and tapwater, mainly. Algae IS a phosphate test. Your box test can say zero, and the algae will say, yep, you have it, because it's bound up in the algae as it soaks out of the rock. Probably the tufts are right where it's soaking out.

^^^ This. You have something going on that your water tests can't pick up because the algae is getting to it before you can.

Last time I had this problem, I removed everything except my skimmer and powerheads, added some Chaetomorpha and the algae was all gone within 2 weeks. I no longer run a filter, just skimmer and everything is status quo. Not that I recommend running without a filter but I found I have enough live rock for filtration and if I didn't change the filter media often enough, it would create more problems than it solved.

Note: If you are using tap water, stop immediately. Even with conditioners it won't remove the phosphates. If you don't have an ro/di source at home, your local grocery store will likely have some sort of ro/di or purified water that you can use for top off.
 
Red and Green LEDs are personal preference, I run them somewhat low and only have them on for added color for my eyes. 400nm to 500nm is the light spectrum you need.
 
^^^ This. You have something going on that your water tests can't pick up because the algae is getting to it before you can.

Last time I had this problem, I removed everything except my skimmer and powerheads, added some Chaetomorpha and the algae was all gone within 2 weeks. I no longer run a filter, just skimmer and everything is status quo. Not that I recommend running without a filter but I found I have enough live rock for filtration and if I didn't change the filter media often enough, it would create more problems than it solved.

Note: If you are using tap water, stop immediately. Even with conditioners it won't remove the phosphates. If you don't have an ro/di source at home, your local grocery store will likely have some sort of ro/di or purified water that you can use for top off.
Thanks, no tap water here. I'm working on lowering nutrients as well.
 
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