ORP and algea?

[extremepcs]

Hi all,
I installed an AquaController 3 on my 4 month old 125g reef tank 2 weeks ago. I'm using it to monitor Ph, temp, and ORP. It also controls all of my lighting.
My ORP readings are averaging 215. Is that too low? Could it be the/a cause of algea? I've been having moderate green algea problems for about 1 month... just on the glass, no hair algea. Ph is averaging 8.3, temp about 80. Nitrites are 0, nitrates 0-5. Should I look at getting a ozonizer, or are there any "home remedies" to raise ORP (if it needs to be raised).
I don't think my lights are causing the algea, but I could be wrong. I have (3) 150w MH. I have had the algea problem since before I added MH lighting. I do a 1/4 water change twice a month (RODI water) Here's my current lighting schedule:
7 AM - Actinics on
9 AM - first MH on
10 AM - second MH on
11 AM - third MH on
1 PM - first MH off
2 PM - second MH off
3 PM - third MH off
5 PM - Actinics off
Any suggestions would be appreicated. Sorry for rambling

Thanks!

 

[extremepcs]

I forgot to mention that I am using a skimmer (Coralife Super 220g) and it is working well.
I have a 55g sump, 175lbs. LR, 40lbs. LS. 1200 GPH pump. I have a lot of cheato in the sump.
Fish - 1 coral beauty, 1 naso tang, 1 mimic tang, 1 scopas tang, 2 small perc clowns.
Inverts - 25 astrea snails, 10 nass. snails, 5 emerald crabs, 2 cleaner shrimp, 30 hermits (blue leg and scarlet), 2 cleaner shrimp, 1 coral banded shrimp, 1 bubble tip anemone
Coral - 1 green star polyp, 1 xenia, 1 green zoo. All are about the size of a baseball.

 

[tahoetanks]

Maybe feeding too often or too much? I'm having an algae outbreak myself right now. I cut back on the feedings and started doing 10% water changes every week. It's starting to slow down. What are your tank parameters?

 

[hatessushi]

ORP should not be considered as a whole cause for algea. Usually it's caused by to many nutrients in the water as well as phosphates, and nitrates. Overfeeding is one cause, using tap water can be another.
ORP is Oxygen-Reduction Potential, it is the measure of a system's capacity to oxydize material. You can have to much redox or to little. Redox potentials above 400mV are dangerous to life. Ideally you want a range of 350 to 390 mV. Most properly set up and maintained systems display an average of 300 to 340 mV, some may vary down to the 200s, but values below 300 mV should be a signal that something is wrong.
Redox fluctuates in the wild and in captive systems throughout the day. Dissolved oxygen, pH, feeding, cleaning, lighting, and more all affect ORP. When the lights switch on and photosynthesis starts, metabolites released into the system will start loweering redox after an initial small spike (due to increased oxygen from photosynthesis). When the lights go off, and macrolife settles down, fewer metabolites are produced and ORP increases again. Redox tends to drift downward during the day, reversing the trend at night.
Knowing what your system's usual ORP signature is during a given interval, and seeing a sharp loss (anything around 50mV) or a steady loss (5 to 10mV net loss per day) should lead you to further investigation and action. Is there something dead and decomposing in the system?

 

[hatessushi]

Oh, the best way to keep your ORP in a good range is to practice good installation and maintenance of equipment. Make sure your skimmer is working properly. Your pH looks fine. IMO you want to have some algea because you have tangs and they like to graze on algea all day long. I have algea on the back of my tank and everyday I brush it off the front and sides. My Kole Tang love to boounce his lips off the back of the tank all day long and has given the background a blue with black textured look. the algea is not black but just looks that way with the blue background. It is brown algea. If you have lots of algea that is out of control and since your nitrates are fairly low take a look at your phosphates. If you can test for it and find it's to high then you might want to look at a phosphate reactor which run about $29 to $40.

 

[extremepcs]

Thanks for the great info! I don't have anything dead in the tank that I know of. Everything is accounted for. My hermits have killed a few snails... I do leave the empty shells in there for the hermits.
As for feeding, I use 1/2 a cube of Emerald Entree once a day. The fish seem to eat all of it. I also spot feed the anemone 2 times a week. I feed it a small chunk on raw shrimp or scallop. He gobbles it up. The 2 clowns eat any small bits that are left over.
I'll pick up a phosphate test this weekend.
Thanks again.