5 Steps that will cure GHA (Guaranteed!)

[Eric45]

1. Reduce MH lighting to 4 hours per day
2. Reduce temp. to about 76/77 (algae grows better in warm water)
3. Use gfo at the correct pump pressure (slow)
4. If you have a DSB older than 3/4 years, get rid of it. Leave an inch or so for appearance. (this will eliminate any nitrate issues)
5. Reduce feeding to a minimum and wash food under tap water to eliminate excess Phosphate. (every other day is not unreasonable)

Do these things and within a few months you will have won. The key here is knowing that it isn't something that you can cure overnight or with some magic potion. It's a siege not a pitched battle.

But in the end, its about Phosphate and light.

[brandon429]

What do we do about the tanks doing that which still have gha

We can post threads if needed, some years into the battle

[Eric45]

My view is that one or more of those five steps is not being carried out. Food is the only way I know of that PO gets in the tank. And algae needs light to grow. Cut both back far enough and the result is inevitable -- given the other essential element -- time.

[dowtish]

These 5 listed are just a few things that MAY help and there are many variables to each persons tank that these 5 are not always guaranteed.

DSB and MH lighting for one is not typical in most setups today either. What about large fuges with macro algaes, GFO, Bio-pellets?

[Eric45]

I thought about including fuges but decided they are not critical to a solution. Maybe gha gets to the PO first, I don't know. I used 'fuges off and on and they didn't 'appear' to make a tangible difference.

I talked about gfo and I think plenty of people are still using both MH's and DSB's.

[brandon429]

I do think they are great preventatives where if you start a tank with that care in mind a lot less algae incursion would occur...most are asking for help after an invasion sets in

[Eric45]

My advice was to folks who are dealing unsuccessfully with the problem.

[sirreal63]

None of those guarantee success at beating algae.

1. Reduce MH lighting to 4 hours per day
Algae can and will be perfectly happy with 4 hours of lighting a day.

2. Reduce temp. to about 76/77 (algae grows better in warm water)
Temp is not the limiting factor here, and many of us run our temps to the mid 80's with no algae issues.

3. Use gfo at the correct pump pressure (slow)
Slow flow is meant to keep the GFO from abrading and releasing fines to the tank and has little effect on the absorption rate.

4. If you have a DSB older than 3/4 years, get rid of it. Leave an inch or so for appearance. (this will eliminate any nitrate issues)
If the DSB is functioning correctly, it is processing nitrates, not collecting them. Depending on how a DSB is removed, you could actually crash a tank by removing it.

5. Reduce feeding to a minimum and wash food under tap water to eliminate excess Phosphate. (every other day is not unreasonable)
The packaging water in food does not contain the bulk of the po4 in food, it is contained in the food itself, and is what makes it food. With the potential high level of phosphate in some tap water, you really haven't gained anything.
http://www.advancedaquarist.com/2012/3/chemistry

It is true that doing some of the above may help in one tank, it could be a disaster in another. As noted algae needs light and nutrients to grow, you don't really want to limit the light but you can work on the nutrients, depending on the source. If the source is po4 laden dry rock and someone did nothing to remove that po4 before setting up the tank, you now have a fertilized bed for algae to grow, it won't matter much how free of po4 the water is, the algae is consuming it from the source, not the water column. Eventually with po4 and no3 in the correct amounts to sustain life in the tank, the po4 from the rock will be used up or leach out to equilibrium with what it is in the water. The length of time it can take to do this will depend on how much po4 is there.

There is no sure method of eliminating algae that will work on every tank. The best we can do is try to find the source of the nutrients and work on eliminating it.

[Eric45]

Perhaps my use of the term guaranteed is not quite accurate. I should have said guaranteed in the vast majority of gha cases. These I believe are mostly attributed to too much food. People have a compulsion to feed.

As for DSB's I entirely disagree. From my experience, eliminating it dropped my nitrate immediately and to almost zero. Haven't had any nitrate issues since and that was over a year ago.

Same experience with light. Going from 8 to 6 to 4 made a significant difference in algae growth. And my guess it that a majority of reefers are still using MH's and waiting for LED's to be more proven and less costly.

The temperature suggestion comes from my experience with swimming pools where algae grows far more quickly as the water warms.

[sirreal63]

You are assuming that your DSB was functioning correctly, if you were having nitrate issues, clearly it was not. Removing a DSB that has become a sink hole of filth opens up the possibility of releasing that filth into the water column. The method of removal makes a difference.

The import of food should match the export of excess nutrients, when they do not match is when problems occur. If your export methods are good, you can feed more, and that should be our goal here, to feed enough to have the life in our tanks thrive and to be able to process or remove the excess. We see starving tanks here almost daily and that comes from not understanding export. Some types of algae are far better at consuming nutrients than our corals are, you cannot easily starve these algae out without also starving the corals in the tank. :-)

I truly wish there was a single method that worked for everyone the same, every time.

[Eric45]

I still say mine would work for most tanks with algae problems. And I think all dsb's become nitrate sinks after a while because there's not any maintenance you're supposed do on them right? You don't vacuum...what else is there.

DSB's don't work over time, if you're having nitrate problems and the dsb is over three years old, strongly consider getting rid of it.

[sirreal63]

Of course you can maintain it, though my own experience differs from much of his advice, it is still a valid way to keep your DSB clean and functioning. However it may not help a DSB that is not functioning correctly. I don't advocate DSB's in a display but there is nothing wrong with having one as long as it is set up properly and has the life in it necessary for processing nutrients.

Something to consider...