Last resort for GHA?

[oakengineer]

I've had a reef tank for about 2 years, and have been fighting a major GHA problem for about 1.5 years of that. So far I've tried the following:

• Feeding less (currently at 2 Aquadine flakes twice a day)
• Reducing number of fish (had 5, now down to 3)
• GFO reactor (with BRS High capacity GFO)
• Chaeto in the sump
• lots of manual picking
• Semi-weekly 15% water changes
• More cleanup crew
• Reducing light levels/duration
• 3-day blackout

65 gallon w/10 gal sump
Current Orbit Marine LED system
Established and maintained with RODI water

Here are the tank parameters: (using api test kits)

• temp: 78 degrees
• Salinity: 1.025
• Annomia: 0ppm
• Nitrite: 0ppm
• Nitrate: 0ppm
• Alkalinity: 7 dKH
• Calcium: 440ppm
• Phosphate: 0ppm
• Magnesium: 1300ppm

Current stocking:
2 medium clownfish
1 orchid dottyback
1 fire shrimp
Lots of Zoas, LPS, some SPS

On paper I feel like I'm doing everything the way you're supposed to. I know most people think nutrients are the problem, but I don't see how I can possibly reduce them further without getting rid of more fish. 3 small fish doesn't seem over stocked for a 65gal. The only thing I can figure out is that the phosphate must be coming from my rocks. I bought 80% of them from a local guy for next to nothing. is it worth tearing apart my tank to see if that is causing the problem?

Here's a picture of the current setup:

 

[Bent]

Ok here's my .02 cents.

You have a nutrient problem from somewhere. After 2 years and a light bio load it makes me suspicious of the source water. Are you using RO/DI? The po4 readings are misleading because the algae is pulling it out of the water column. If you have algae, you have a nutrient problem regardless of what any testing says. You need to nail down the source, and like I said I'm suspicious of the source water, so let's work and try to see if we can figire the source out.

 

[oakengineer]

Ok here's my .02 cents.

You have a nutrient problem from somewhere. After 2 years and a light bio load it makes me suspicious of the source water. Are you using RO/DI? The po4 readings are misleading because the algae is pulling it out of the water column. If you have algae, you have a nutrient problem regardless of what any testing says. You need to nail down the source, and like I said I'm suspicious of the source water, so let's work and try to see if we can figire the source out.

I established and maintained the tank with 0 TDS RODI water.

 

[billdogg]

I suspect the rock is the culprit. As an experiment, take a piece out, scrub it as clean as you can in used tank water, and then place it in a bucket of freshly made saltwater (tested for 0 PO4) with a powerhead and if you have it, a small heater, no lights. Let it go for a week or so and then test that water. If it test positive for PO4, you have your answer.

 

[Bent]

I suspect the rock is the culprit. As an experiment, take a piece out, scrub it as clean as you can in used tank water, and then place it in a bucket of freshly made saltwater (tested for 0 PO4) with a powerhead and if you have it, a small heater, no lights. Let it go for a week or so and then test that water. If it test positive for PO4, you have your answer.

That was my next suggestion.

Have you tried to vodka or vinegar dose with your GFO and turn the lights off for about 3 days?

 

[Sk8r]

I have one question (though the rock is a good suggestion)---did you change the GFO every month? The stuff can 'saturate' in a week and then absorb no more, ever. Changing it monthly disposes of a load of phosphate every month, at least.

 

[oakengineer]

I have one question (though the rock is a good suggestion)---did you change the GFO every month? The stuff can 'saturate' in a week and then absorb no more, ever. Changing it monthly disposes of a load of phosphate every month, at least.

I change it when I do water changes. So 3 weeks at the latest.

 

[oakengineer]

That was my next suggestion.

Have you tried to vodka or vinegar dose with your GFO and turn the lights off for about 3 days?

I did a 3 day blackout once, but I've never heard of adding vodka or vinegar. Is that something you add to the tank or the GFO? How much?

 

[Sk8r]

Ok, so it did what it could and was still getting more than it could handle. I'm leaning to the rock as a source, as billdogg suggested. Some types of rock are harder to deal with than others. I had about half live rock, but acquired some lovely holey limestone that turned out to be a phosphate factory---it finally cured, but it was a nasty load of it.

 

[anthonys51]

also dont use the api test kit for phosphates. its really not the best. test with salifert

also try changing to frozen food . frozen food is not as concentrated as flake foods. i read someone that 5 grams of flake is enough to give you phosphorous reading of .4 in one feeding in a 100 gallon tank. also in order for cheato to work effectively you really need to slowing turn it, where you doing that plus 10 gallon refugium really isn't enough to do a dent in a 65 gallon tank

i would take the rocks out and rearrange them. they seem to be in a big pile with little flow in between them, open them up a little and clean the off before rearranging them

 

[Sk8r]

I've dosed vinegar but not in combo with lights-out and gfo. This is a new one on me. Vinegar dosing is by a table: you increase the dose per gallon gradually, over a number of weeks. It provides a carbon source, which (the chemistry eludes me) somehow involves both phosphate and nitrate in an accelerated production of bacteria. But you list 0 nitrate, and that MIGHT affect that process. You're going to need to talk to a chemist on that one. Meanwhile---run Bill's soak-a-rock test, and see what results.

 

[sfdan]

I could never get my sections of hair algae to go away completely even with all sorts of control methods until I got a couple Mexican turbo snails (2 in my 120 -- so 1 would work for you). They just bulldozed the hair algae and got it down to the roots, and once they got rid of the hair algae it never came back. It was actually quite amazing because before the Mexican Turbos I'd had every other type of snail and they were all worthless in comparison.

This doesn't solve the problem on its own, you still need effective ways to export the nutrients (which it sounds like you have), but in my experience the turbo snail actually clearing out the roots was the key in preventing the GHA from coming back as opposed to however thoroughly I was scrubbing it.

 

[hkgar]

I got rid of my GHA in 3 days and had been harvesting a ton of it every day. I also was running GFO and PO4 and NO3 levels were 0.

I lot of work but each day I removed 1/3 of the rock and scrubbed it completely clean of ALL GHA from every hole and crevice. I than sprayed all rock surfaces with hydrogen peroxide and let them set for five minutes. A salt water rinse than back in the tank.

I have not had GHA since, but did make one almost fatal mistake. One piece of rock had some Zoas that inadvertently scrubbed and I inhaled palytoxin and spent a couple days in the hospital.

 

[oakengineer]

Ok, my most algae covered rock is scrubbed clean, rinsed and in a bucket. My phosphate test of the water came back 0. I'll post an update in a week.

 

[CStrickland]

I wouldn't dose carbon in a tank that has zero nitrates. It is a nutrient removal system, it needs to work in balance of roughly a hundred pieces of carbon to twenty bits of nitrate and one phos.

I'm not familiar with that brand, but if they are regular flakes you are way under feeding IMO.

Which brands are you using to test for phos and nitrate? If your phos has been low for months and months, I'd look at stuff settling on the rocks, not leaching from them. How's your flow, can poop land on the rocks and get caught in those green fronds to compost?

how many herbivores? How much and when did you add to your CUC? I'd probs just buy an algae blenny at this point, they're fun fish that eat algae and are happy in small tanks. Lawnmower and starry are good types.

It could be leaching, and maybe carbon dosing (vodka,vin,nopox) will help. But honestly I don't see much support for either. feels kinda desperate.

 

[oakengineer]

Ok, its been a week. I bought a Red Sea phosphate test so I could test more accurately. The water in the bucket with the rock tested 0.12 PPM. The tank water was .08 PPM. Does that confirm its the rock? Could it just have been a little bit of algae I failed to remove?

 

[that Fish Guy]

I used Tiger Trochus Snails.

They are Often Referred to as "The Cadillac of Snails"

I had Hair Algae 8 Inches Long in One Tank (No Joke).

I pulled out as much as I could.

One Week After Getting the Tiger Trochus Snails their was Not One Speck of Hair Algae.

 

[that Fish Guy]

A lot of People are Dosing Their Tanks with Hydrogen Peroxide nowadays with Great Success.

 

[Sk8r]

That reading says to me it's a problem. In just a week it produced that reading. The only consolation is that sooner or later it's almost got to run out of phosphate. Wait til Billdogg chimes in, but possibly setting up 2 cheap bare-bones tank, no sand, no rock, one for corals, one for fish, or maybe a combo of the two, and pulling that rock and treating it aggressively might be the shortest course. It sounds to me like what mine did, lunking along just fine for a year, THEN deciding to dump its phosphate load; only yours is losing it faster than gfo can sop it up, apparently. There are several ways to go about this, but I'm no expert in rock-curing.

 

[oakengineer]

Scratch that. The Red Sea kit tests RO water, fresh saltwater, the tank water, and the bucket water all about the same. .08 ish.

My TDS meter reads 0. So either my phosphate test kit is bad, or both my RO system and my TDS meter are bad.