PH drop / Maroon algae spreading

[04svtfoci]

Hi All,

 

Everything has been great with my tank but a few weeks ago i noticed a maroon colored algae start to form on top of the sand in the corner of my tank which has spread about 1/2 my sand bed now. I have no clue what it is and my daughter lost my digi cam's cable to dload to pc. It seems to sink into the sand at night or atleast diminish and come back when i turn the lights on and is catching air bubbles in it. I also noticed that my green star polyp colony hasnt opened up since yesterday so i did some water tests and my ph has dropped to mid sevens which has never happened before, my amonia is at .1 range barely registering on my test kit and everything else tested well as it always has. Could this algae be the cause of the ph drop by absorbing up either oxygen/co2 and causing an imbalance? All of the other coral and my fish seem to be unaffected.

 

thanks. sorry i cant get any pictures at this time unless i use my cell which is pretty bad lol.

[Origami]

It's cyanobacteria.

 

It could be old lights, or water quality issues, or both. It could also be high organics or DOCs (dissolved organic compounds). Do you run activated carbon in your system?

[angel not fish]

uv sterilizer help a lot.

[zygote2k]

uv sterilizer help a lot.

UV sterilizers don't help control cyanobacteria.

[04svtfoci]

I dont have a very complicated set up, i have a seaclone 100 skimmer and an emperor 400 bio wheel on my tank for filtration. i change the filter cartridge every week or two, and i have a foam pre filter. i did recently add fish to the tank, i have 2 clowns and a yellow tang. could it be that i over fed which caused it to show up? My lights are not quite 6 months old, t5's 10k day light and a 6.5k actinic i think it was. As far as carbon goes the only carbon i know of is in my filter cartridges. Is there any way to get rid of the cyano?

Edited September 25, 2011 by 04svtfoci

[matt bills]

Will taking the carbon out fix it I have the same problem?

[Origami]

Your skimmer may be underperforming (Seaclones don't have the best reputation.) and your biowheel may be raising your nitrates by providing a highly-oxygenated environment for aerobic bacteria, which efficiently break down ammonia into nitrite and then nitrate, but which are ineffective in converting the nitrate to nitrogen gas (the forte of anaerobic bacteria). (This may not be such a big issue if you're running a fish only tank.) However, I doubt that there's enough carbon in the filter cartridge to remove the organics that aren't being removed by the skimmer or broken down by other processes. What is your maintenance schedule like? How often do you do water changes and how much each time? Do you have a fish-only system, or do you have a reef tank? Sometimes you can actually see the effect of high dissolved organics by noting yellowing of the water from those organics (aka gelbstoff - German for "yellow matter") You may want to consider several large water changes to remove pollutants in your tank, in addition to either more frequent water changes or improved filtration.

 

Once you clean up your water, siphon the cyano off of the surface of your sand once or twice a day. Eventually, you'll get it under control.

 

There are chemical means of controlling cyano, also. One such product is Red Slime Remover. These additives address the symptoms but don't fix the conditions which set up the problem in the first place. Depending upon the type of tank you have set up, you may or may not want to consider relying upon this sort of fix.

[matt bills]

Thanks Tom good info

[04svtfoci]

The ammonia was only slightly up, the nitrate and trite were showing the complete bottom of the scale on my test kit. I figured the skimmer was not the best, could i add carbon to my prefilter? or maybe double up the filter cartridges. i do a 5 to 10 gallon change every week, depending on how much time i have to make ro water my unit is only a 50gpd so it takes a lil while and my weekends are fairly busy. and my tank is a reef, 70lbs live rock, assorted zoas, torch corals, green star polyps some ricordea and regular mush rooms etc. and 1 tang and 2 clowns. 55 gallons total.

Edited September 26, 2011 by 04svtfoci

[Origami]

It sounds like you have enough live rock in the system that you really don't need the biowheel on the HOB filter, but since your nitrates are just fine, your probably don't need to do anything at this time.

 

I tried to find the reference to an article that I once read about a quick way to "see" high organics in water, but didn't have luck. If memory serves, it went something like this: Take two white index cards and color one of them a light yellow. Tape both to the end of your aquarium glass (on the outside, of course), and view them from the other end of the aquarium. If the yellow card does not clearly stand out from the white card, your water is yellowed (i.e. has high dissolved organics). This can lead to low pH(organic / humic acid formation) and problems with some algae and cyanobacteria. (There's a good summary article here.)

 

I haven't any idea how large your prefilter is, but you may want to consider a small HOB media reactor like a TLF (two little fishies) and run a cup of so of fresh, rinsed ROX carbon in it, after doing some water changes and siphoning off the cyano.

 

BTW, cyano is photosynthetic. That's why you see it suddenly spread during the lighted hours and fade in the darkened hours.

[04svtfoci]

Awesome, i appreciate the info. This is my first tank and i feel like i had been lucky so far that nothing strange has happened. Thankfully this doesnt seem to be to bad and i can remedy it with some changes to water and siphoning and a reactor. Any recommendations on a better hang on skimmer? i was looking at CPR and a few others.

[Origami]

If you come up with a budget figure and post another thread looking for recommendations on a HOB skimmer, I'm sure that you'll get lots of recommendations from people with experience with specific models. I had a CPR bakpak once. I don't think that I'd go with it for a 55. Maybe an AquaC Remora Pro, a Deltec MCE300 (BRK's a Deltec vendor), Octopus BH800 (See Fins and Feathers for an Octopus skimmer)... these are just some that come to mind.

[04svtfoci]

Ok, i went to the store and found some bags of activated carbon meant for a canister filter and rigged it up to sit in my pre filter spot before my carbon filter so i have an extra 200grams of carbon in the tank that it has to filter through for now. I also bought a ph buffer and added some to the tank and scraped all the cyano out of the tank that was visible taking part of the sand bed with it to try to get as much as possible. I will let it rest for a few days and do a test and see where i am, and hope everything turns out well.

[Origami]

Good luck. Also, remember that a good water change is always effective in knocking back pollutants. A 25% change knocks 25% off, etc.

[04svtfoci]

Well everything seems to be returning to normal in my tank, i still am seeing some stuff on the rocks but i am cleaning them off with tooth brush and turkey baster , although when i was siphoning up cyano i came with in about 3 inches of my fav ricordea mushroom that had recently split in two and it went flying into my hose and was mangled pretty badly.