Green Hair Algae

[Bob5920]

As promised I measured the Phosphate levels at three points; the incoming water after the ro/di system, the premixed saltwater, and my tank.

A.) incoming water =0.0 mg/L
B.) pre-mixed salt water = 0.0 mg/L
C.) tank = 0.5 mg/L

You were correct in the assumption that my phosphates were high. With the incoming water filtering system in place I seldom measured PO4 because I thought that the main source was either incoming water or the salt mixture.

Two questions.

1. Where's it possibly coming from?
2. Recommendations for reducing it?

I have a 240 gal FO tank & 60 gal sump with some agressive & large fish. Lion Fish (~6"), Puffer (~6"), a trigger (~4"), yellow tang( ~4"), fox face rabbit (~4") and 4 Blue Green Chromis (~1-2"). I have DSB (5") and a protein skimmer.

My two big eaters are the puffer & Lion fish consuming 3 krill each twice a day. The others either eat brine shrimp or worms.

Now that I'm writing this I remember that frozen food may have phosphates. Possible? I don't rinse it before putting it into the tank.

 

[mr_fosi]

Two questions, two answers.

1. Either from your LR, your feeding or death(s) in the tank.
2. Where do you see it? If it is isolated, it may be the rock. If it is widespread, it is from death or feeding.

The fact that your 240+60 is FO and has aggressives in it tells me that you are probably feeding them juicy foods and you are probably doing it often. You can reduce your nutrient input by straining any juicy foods and cutting back on feedings.

The DSB may be good for denitrification, but it could be a source for PO4. PO4 that is precipitated out can be resolublized by the strongly reducing DSB. I doubt that this is a major feature, however. You probably just need to control your food and feedings.

Strain the brine and worms. Are the krill frozen? Strain them too. How sloppily do they feed? Are you sure they need to eat so often? I have never kept big or aggressive fish but I have found that the fish I have kept were able to survive on a lot less than every-other-day, all-they-can-eat-in-two-minutes feedings.

You can also use a PO4 absorbing media if you like but media doesn't solve the problem and it costs you $$.

 

[Bob5920]

I see it on the live rok but it also grows from the sand bed and on the back walls.

The krill is frozen.

I don't have any inverts to help clean up the waste because the trigger & the puffer love to eat them.

The lion eats the krill whole and the puffer nibbles on it from a feeding stick. They will typically eat their fill in the 2 minutes. If I skip a feeding they get more aggressive at the next feeding and eat more then typical.

This type of tank wasn't my plan but stuff happens. I thought a fish only tank would be easier to maintain then a reef but this one is a challenge. My 65 gal reef is doing great.

I cut back on the lighting about two weeks ago, which did slow things down. I just ordered some cerith and nassarius snails to help with the waste since they like to bury themselves. I do know that eventually the puffer and trigger will get them because both love to 'play in the sand'.

I will rinse the food from now on and cut back on the feeding to see what happens.

Do you think vaccuuming the top of the sand and the rocks will help or will it remove some of the helpful bacteria?

 

[Bob5920]

I'm been out of town for about a week and was finally able to do my routine GHA harvesting. I think I may have found the source for the PO4 increase. Prior to this posting I was advised to turn off my MH lamps since this was a FOWLR setup. The intense lighting may be causing the GHA to grow out of control. It's been two weeks since I did that and today I noticed that the GHA pulled up without any force. I'm assuming die back, I believe probably caused the PO4 increase.

I'm still going to do what I said before, but I believe the main breakout has been temporarily corrected.

Why Temp? If I want to add corals to this tank and turn on the MH then will the GHA return?

 

[mr_fosi]

Do you think vaccuuming the top of the sand and the rocks will help or will it remove some of the helpful bacteria?

Vacuuming shouldn't hurt anything so long as you don't dig in the sandbed. Disturbing the DSB = bad.

I think that GHA dieback could be the culprit but it is hard to know for sure. You did have a GHA problem before you turned the MHs off which suggests that you had a PO4 problem as well.

GHA does really well under MH (especially 6700K-10000K) but it will tolerate low light levels well. You need to control the nutrients, especially the PO4 before you will be able to get a handle on it.

 

[bastanford]

my recommendation would be to somehow incorporate some macro algae (i.e. caulerpa) into your sump somehow. this will easily take care of your phosphates.

 

[Bob5920]

I have mangroves that has brought down my Nitrates. It appears that my Phosphates are coming down. The measurement system that I use has poor resolution so I'm halfway between the 0 color and the .5 color.

I also found that my Alk is a little low so I'm bring that back up slowly.

 

[mr_fosi]

Glad to hear the PO4 is on its way down.

Be careful what caulerpa species you use. Some are more prone to "going sexual" than others and some are more invasive than others.

I use Chaetomorpha sp. in my tank.

 

[bastanford]

i honestly have no idea what species it is. it has a very broad leaf. the guy at the local fish store recommended it, so i took his word. i've had it in my refugium for about a year and it has pretty much stayed put. does anyone know of a good reference book on Marine Aquarium Algae that covers both the nuiscance and desired varieties?

 

[mr_fosi]

I don't know about a reference book but this Link can provide some help.

The most common species I see are Caulerpa bikinensis (cup caulerpa), C. taxifolia (feather caulerpa, illegal in coastal states), C. sertularioides (feather caulerpa), C. racemosa (grape culerpa), C. serrulata (razor caulerpa), C. peltata (button caulerpa) and C. prolifera (often simply called "caulerpa").

C. prolifera doesn't "go sexual" but I have experienced, either in my tanks or in the tanks of others, all of the others doing so.

"Going sexual" here is a misnomer since the catastrophic reproduction whereby the macroalgae convert their cellular contents to reproductive cells is generally a form of asexual reproduction in response to a stressor or a change in environment.

EDIT: I did find this book... Can't vouch for quality though: "Algae: A Problem Solver Guide" by Juien Sprung. You can find copies of it on Amazon.com for $10.