Serious Algae issues on sand/rock. What am I missing?

[Lee]

My tank is over 1 year old, as are most of the inhabitants, less a few corals

Ammonia: 0
Nitrite: 0
Nitrate: 2
Phosphate: 0
Lights: Tek T5, bulbs probably about 1 year old

I do not overfeed. I feed 2 cubes of frozen every day to some big fish. Nothing goes un-eaten. Lights are on 8 hours a day, but within 3 hours, I've got a thick coating of brown algae on the sand and even on some rocks. CUC consists of 25 astreas, 15 nassarius, and 5 hermits.

#1) The CUC might be a little small, but I larger CUC will do nothing to slow the rapid algae growth, so this isn't the solution I'm looking for

#2) The only problematic area I can think of is that the bulbs may be up to a year old. But I was having the same problem before I bought this light fixture, and my previous lights were new.

Is there anything I am missing that could be causing this rapid algae growth? Any solutions?

 

[Shermy]

Flow?

We had a HUGE problem with algae, our prams were fine and we had no idea what was going on. Come to find out our pump was clogged up with micro algae, we didn't notice the flow decreasing because it happened so gradually. Once the flow was back up, we added a turbo snail to clean up the big stuff and we have been fine for the past couple of weeks.

I do miss the turbo snail though, he was just to clumsy in a small tank.

 

[nikkipigtails]

My first thought is: STOP FEEDING YOUR FISH SO MUCH!!! Are you skimming? Fish only need to be fed every other day. This is the root of your problem.

The cyano is caused by excess nutrients in the tank. Even though you say that they eat everything, when you feed frozen food, small particles that you don't see go uneaten and settle on the sand and the rocks. If you have an insufficent cuc, then you'll get the cyano problems. Also, try directing more flow at the sand. What size sand are you using? Is it crushed coral or sand?

What kind of fish do you have and what size tank do you have?

My second thought is: that you definately need a larger cuc. Toss the hermits, they don't do much and will kill the snails that are working just for the shell. Stock up on the nassarius. They'll help keep the sand stirred. Although they don't eat cyano, they'll help keep your sandbed stirred and they'll eat whatever settles on the sand like detritus and extra food (even the kind that you can't see).

My third thought is: that your lights are due for an update.

 

[sambrinar]

Also you need to soak your food, all of it, flakes included, if you feed those in ro/di water for about 10 minutes. all prepared foods have phosphates in them for preservatives.

I did an experiment and prior to soaking the food the phos was off the chart, after soaking it was .25. huge difference

 

[johnmaloney]

The CUC would eat the algae though so it wouldn't be able to multiply so I think it would help. Also your paramters are good after the algae consumes nitrate and phosphate. How is your silica?

 

[Lee]

Flow?

We had a HUGE problem with algae, our prams were fine and we had no idea what was going on. Come to find out our pump was clogged up with micro algae, we didn't notice the flow decreasing because it happened so gradually. Once the flow was back up, we added a turbo snail to clean up the big stuff and we have been fine for the past couple of weeks.

I do miss the turbo snail though, he was just to clumsy in a small tank.

I do have pretty good flow. I have 2 1200gph powerheads along with my sump return. If I aim them too far down, they'll kick up the sand and make big sand dunes. So my powerheads are aimed as close to the sand as they can without making dunes

 

[Lee]

My first thought is: STOP FEEDING YOUR FISH SO MUCH!!! Are you skimming? Fish only need to be fed every other day. This is the root of your problem.

:bugout: < Thats the look on my face right now. I thought I was underfeeding. I only feed them once per day because I'm lazy. I thought I've read on here that most people feed 2-3x per day? Did I just make that up?

*edit* forgot to mention, yes I do skim, 24/7. Its in the sump, and there's a fuge on the other side with cualerpa and cheato

The cyano is caused by excess nutrients in the tank. Even though you say that they eat everything, when you feed frozen food, small particles that you don't see go uneaten and settle on the sand and the rocks. If you have an insufficent cuc, then you'll get the cyano problems. Also, try directing more flow at the sand. What size sand are you using? Is it crushed coral or sand?

Good explanation, thanks! Regular sand, not crushed coral.

What kind of fish do you have and what size tank do you have?

90 g, Perc pair, yellow tang, a few small chromis, flame angel, blue tang, pinkspot watchman

My second thought is: that you definately need a larger cuc. Toss the hermits, they don't do much and will kill the snails that are working just for the shell. Stock up on the nassarius. They'll help keep the sand stirred. Although they don't eat cyano, they'll help keep your sandbed stirred and they'll eat whatever settles on the sand like detritus and extra food (even the kind that you can't see).

Anything else for sand besides nassarius snails? Thats why I bought the crabs, but they ended up being worthless creatures whose only function is hunting and killing innocent snails.

My third thought is: that your lights are due for an update.

I will do this

 

[Lee]

Also you need to soak your food, all of it, flakes included, if you feed those in ro/di water for about 10 minutes. all prepared foods have phosphates in them for preservatives.

I did an experiment and prior to soaking the food the phos was off the chart, after soaking it was .25. huge difference

My phosphates are not even registering on the test kit they are so low. Interesting info though

 

[Lee]

The CUC would eat the algae though so it wouldn't be able to multiply so I think it would help. Also your paramters are good after the algae consumes nitrate and phosphate. How is your silica?

I've never tested for silica. You mean silicone dioxide, SiO2?

 

[lcstorc]

A common misconception. Try the test for yourself. You don't register the phosphates in the tank because the algae is thriving on the phosphates in the tank.
Are you feeding the tangs nori? Tangs naturally eat a lot of algae though usually not the nuisance algae we have in our tanks. Get them some nori to supplement their diet and then cut way back on the frozen food and rinse it well before feeding.
You say you are feeding 2 cubes a day, but 2 cubes of what? Is it the same thing every day? May not have anything to do with the algae but certainly has something to do with the health of the fish.
Also you do not mention your water source or water change schedule. Both can be very relevant when fighting an algae issue.

 

[Lee]

A common misconception. Try the test for yourself. You don't register the phosphates in the tank because the algae is thriving on the phosphates in the tank.
Are you feeding the tangs nori? Tangs naturally eat a lot of algae though usually not the nuisance algae we have in our tanks. Get them some nori to supplement their diet and then cut way back on the frozen food and rinse it well before feeding.
You say you are feeding 2 cubes a day, but 2 cubes of what? Is it the same thing every day? May not have anything to do with the algae but certainly has something to do with the health of the fish.
Also you do not mention your water source or water change schedule. Both can be very relevant when fighting an algae issue.

I do feed Nori, usually twice a week.

Cubes are at random, 2 of the following: Brine Shrimp, Mysis Shrimp, Emerald Entree, Spirulina Brine Shrimp, Marine Algae mix, Krill, and another one that is a mix of just about everything previously listed. I literally just pick a random 2 everyday, balancing them all out. Along with veggie flakes sometimes in the morning, and the Nori already mentioned.

H20 source is 5 stage RO/DI, change about 20 gallons a week. About 25% weekly

 

[Lee]

Would a phosphate sponge have any positive affect? Maybe I can pull them out before they get eaten by the algae...

I was previously convinced that my storage tanks were leeching phospates, but then they tested zero...

 

[johnmaloney]

Here is the test kit for bio-available silica:
Salifert Silicate Test Kit, Silica Kits > Test Kits > Saltwater Aquarium Supplies

Silica is what is feeding your diatoms. Clean up crews do help keep the aquarium clean though, Clean up crew - 3reef Forums

Is your chaeto and caulerpa growing? If not you might have a problem with too much phosphate and not enough nitrate. Nitrate should be at a ratio of 20:1 - 10:1 matched against phosphate for adequate removal. Right now the cyano is might be getting all your phosphate.