another Cyano Question - please help

[Sea Serpent]

Hi - my tank is having a very ugly cyano bloom - and I need help to get rid of it . . .I have gone the syphon, water change, cut back on feeding route and it still comes back in 2 days. By the end of the photoperiod everything is covered again. HELP!

72 bowfornt - over 2 years old
6 inch southdown sandbed about 1 year old
2 250 10K Iwasaki (changed bulbs 1 month ago)
2 110 VHO actinics (changed bulbs 5 months ago)
about 80 pounds of live rock - just took out 50 pounds a month ago for better circulation
AquaC EV90 skimmer with mag 5 - seems to be working well
mag 9 - stepped down to a "7" for return.
600, 400, 400, 1200 maxijets in the main tank
Just added a hang on refugium

purple tang, flame angel, 6 line wrassse, yellow fang blenny, 2 green coral gobies, neon goby - had all for over a year. fire shrimp, greeen serpent, snails and crabs.
got rid of most of my softies, got many sps.

The only REAL change I have made is to take out some of the rock. I did this for 2 reasons: to give more circulation, and to increase the sand surface area. (I was still having trouble with nitrates, even with the dsb.) Could this problem be from that?

Any suggestions as to what to do to get rid of this annoying Cyano? I have done 2 25% water changes with RO/DI water in the past month.

I hate to use chemicals, but I am getting desperate. I would put out the lights for a few days, but my sps corals might suffer.

Sea Serpent

 

[newkie]

Welcome to the slimey world of cyanobacteria. The things to look at with this plague are nitrates, silicates, and phosphates. If you're nitrates are >=10ppm you might ask yourself why. Is your skimmer up to the task, are you feeding too much, time for a water change, do you need to beef up your cleanup crew, maybe macroalgae for nutrient export, would your tank benefit from a dsb? Next your water, is this tap water or purified? If tap test it! Does it have nitrates, phosphates, or silicates? Probably. Cyano forced me to purchase an RO/DI unit. With no incoming phosphates or silicates the building blocks are essentially missing and with no nitrates the nutrients are gone as well. Lastly, this topic is very well documented. Search threads here and read up about them in your books. HTH

 

[wade1]

Actually, contrary to popular myth, cyanobacteria are in no way dependant on nitrogen source in the water (ammonia, nitrite, nitrate, etc) as they have specialized cells capable of converting N2 to usable nitrogen. So, thats not really a worry, although it could readily excaserbate an existant problem.

Secondly, good rock is just as useful at converting nitrates to N2 as is a deep sand bed.

As for issues, I would highly suggest you back up and look at your incoming water source. Are you using RO/DI? Are the cartridges bad? Has something changed in the incoming water? (You can call the water management people and get a free copy of their reports listing everything in the system) Removing some rock might have stirred things up a bit, but that should calm down fairly quickly. Keep up with good quality water changes (check incoming water for phosphates) and keep up good filtration/skimming. Maybe even reduce feeding load.

Now that I think of it, describe the algae you are seeing for us... texture, color, consistancy, etc...

Wade

 

[Sea Serpent]

Hi Wade and Newkie - thanks for the replies -
I realize that I had forgotten to post my chems . . duh . . . That would help. But it gave me a reason to re-check the chems AND the sourcewater as you suggested. Also forgot to mention that I have a Precision Marine Calcium reactor going - so no kalk drip. I use RO/DI water for makeup - about 1 gallon per day.

Amonia, Nitrite = 0
Nitrates = 10mg
Phospates = .5
PH = 8.1 - 8.4 at end of photoperiod
Calcium = 490
Alk = KH 14 !!!! (meq/l 5)

Sourcewater (I tested my stored barrel of RO/DI) has NO phosphate, NO nitrate

The algae is a deep maroon color, mat-like and has lots of air bubbles in it. It is on the sand, and the rock and any "dead" areas on corals. I can blow it off with a turkey baster. I have syphoned it off, and done water changes but it keeps coming back.

My ALK seems awfully high . . . and calcium is a little high as well. Shoud I lower it? What is the safest way to lower it?

Thanks for any help you can give me.
Sea Serpent

 

[wade1]

I wouldn't worry too much about the alk and Ca... I run mine a bit hotter than that even. You can slow the reactor just a notch, but the real problem is the phosphates. Any detectable is a real reason for cyano to be in the tank. I would suggest you look at your reactor media as a possible source as well as feeding. Alter your foods and let us know what reactor media you are using... I have had good luck with ARM and I hear the same about GeoMarine.

Wade

 

[Sea Serpent]

Wade - I am using Korallith as media and I have noticed that I may need to replace it in the next few months. Maybe I'll try a diffierent brand - I have heard good things about ARM. I was not aware that this could be a source of phospates. I just sold (a few months ago) a huge black sun coral which was making me "overfeed" the tank. I will try another water change and keep an eye on the calcium reactor media . .
Thanks for the advice. I'll keep you posted.
Paula

 

[newkie]

Korallith shouldn't contain phosphates, although I don't like it because its small grain size has caused clogging problems for me in the past. You should be aware ARM has been "accused" of causing algae problems too. I personally don't believe that. FYI: ARM is available in 50lb bulk from www.customaquatic.com

I think your phosphates are a bit high. That's great you're using Ro/di, if you are changing the filters regularly (double check) at least you know its coming from feeding or some other nutrient input. What you input you must output, check and optimize your skimmer. Step up water change frequency, get that phosphate down.

Last thing, a tip for feeding your sun coral. Rather than feed the whole tank including the cyano get a clean bown, fill with tank water, place the sun coral in it, add a little DTs or cryropastes to stimulate a feeding response, then target feed the polyps, and place it back. Do this 3 times per week. I heard a similar trick with clams, I think it will probably work with the sun coral as well.

 

[newkie]

Actually, contrary to popular myth, cyanobacteria are in no way dependant on nitrogen source in the water (ammonia, nitrite, nitrate, etc) as they have specialized cells capable of converting N2 to usable nitrogen.

wade, can you provide any links to more information? wouldn't you still agree if there are detectable nitrates there are probable phosphates too? :?

 

[Emmitt]

Most prepared foods like frozen brine shrimp, bloodworms, etc can introduce excessive phosphates. After thawing, rinse under cold water. Don't add the "soup" left over from thawing to your tank. This doesn't work so well with foods with gel binder, though.

In general, cut back on feeding if only until the bloom is under control. It also wouldn't hurt your corals to decrease the photoperiod for a while.