Black Algae Help

[david40price]

So I have a 400 gallon fish only tank I inherited. I service it as one of my customers. Needless to say, the aquarium was full of problems and had been neglected for some time to the point of negligence.

I have solved all problems but one. I have been battling an algae problem. To me it looks like black algae. It is thick and crusty on the sand. It also covers some of the rocks.

All water parameters are pretty good if not perfect except for extremely high Nitrates. When I say hi, I mean they are off the chart. I know this aquarium did not have any water changes at all for an extensive period of time, probably over 1 year.

I believe this issue is simply a high Nitrate problem and I have started doing large water changes (60 gallons per change) although 60 gallons is a drop in the bucket for 400 plus the sump.

I've attached a picture for reference. Can everyone let me know if I have diagnosed this correctly. I need to solve this once and for all and I've never battled this type of algae or whatever it is before.

Thanks!

 

[Bogue Chitto]

It looks like cyano, but I don't know if it grows in black or not. How does your phosphate look?

 

[Qssygod]

It looks a lot like cyano bacteria to me. It took over your tank. The easiest way to fix this problem is to restart the tank. However there are ways to fight it. There's a lot of threads on here about curing this.

 

[david40price]

Phosphates

Phosphates

These are also high. I've tried to reduce with GFO but so far no luck. I think the lack of water changes for so long are the reason. Starting over is not an option. I can try the red slime remover as I've used it on red cyano. Does it also work on black?

I know it will just come back though if I don't remove the source and that's probably the nitrates and phosphates.

What forum should I look in for this issue? Search wouldn't work for me.

 

[Qssygod]

I've never used any remover before so I'm not sure. Cyano bacteria usually means there's not enough flow in the tank either. Try adding more water flow in the tank too. I had a cyano break out when I started my first tank. What I did was I took it down and reset it up. However my mistake was I accidentally introduced it again [emoji23][emoji28]. Anyways I read something online about increasing the flow of the tank. So I did. It didn't go away right away but I increased the flow by adding more fans and I also scrubbed away the pieces of film I can. Another thing I add was a uv filter. I'm not sure if it helped or not but I bought one anyways. In a few months it actually went away.

 

[Qssygod]

Black Algae Help

Buy a sand shifting star if you can. It actually helps aerate the sand.

 

[Keoki18]

I would not recommend the slime remover as this is just a "Band-Aid" for a much larger problem. Your water quality is what needs to be corrected. Cyano, like most algae, need a plentiful source of Nitrogen and phosphorus to grow. As you have said, there is a whole buffet of it in you water.

Here's what I would do:

Syphon as much out of your tank as possible. DO NOT brush it off or wipe it away. The algae is doing a good job of binding all those excess nutrients. All you have to do is export them out of your tank by sucking it up. brushing it will only allow it to settle again.

Do you have a protein skimmer? If so, great! if not, I would be sure to pick one up. Skimmers can play an extremely important role in exporting nutrients in both reef and FOWLR systems.

Use a media to bind the nutrients. You said you were using GFO. Is it in a reactor? reactors will help ensure the most surface area is being utilized during the removal process. Water changes are great, but you will be fighting a long... LONG battle by only doing that. Not to mention your water bill going through the roof!

Biological control is the last thing I would address, however, snails will help maintain the algae once water quality is controlled. I would not recommend the purchasing of a sand sifting star (Sorry Qssygod, they are neat animals!). Sifters often deplete your sand bed of beneficial organisms, and tend to starve out shortly there after.

Flow will help debride the live rock of any settling algae and detritus. It will also benefit organisms that will fight to utilize the same space.

Hope this helps.

 

[Ejazzle]

I had the EXACT same stuff. Only my nitrates were not high. I had high phosphates but brought them down to a normal level and the black cyano kept growing. Took me months to figure out that my lights were too bright. So finally I changed the photo period/intensity and it has slowly gone away.

 

[david40price]

Thanks everyone for the feedback. The GFO is not in a reactor, just a filter bag however I have it in a high flow area. The tank does not have a protein skimmer. I've tried to get the owner to buy one, but so far no luck. I know that is key to help in this situation. Flow is very good, not a problem at all in that area. I will reduce photo period on the lights and keep up with the large water changes and hopefully it will help. I've put about 2k into it over the past 3 months, so hopefully soon they will budge on the protein skimmer.

 

[A1t2o]

Try adding a macro algae or ATS to the sump, or both. Those are cheap and provide a biological nutrient export. Just get good LED lights for the algae and let them run 24/7. I completely got rid of redslime algae and GHA with just an ATS, I had a skimmer but it quit on me about a year ago and I managed to get rid or the red slime about 4 months ago. GHA still has traces but is rapidly dying off/getting eaten by my hermits.

 

[Sk8r]

GFO should be in a reactor if the tank is above nano-sized. Works far better. Beware of any black stuff in the sandbed. You might stick a soda straw probe into it, being careful not to disturb it, draw it out and test it for smell. If 'rotten eggs' (hydrogen sufide) above all do not disturb it but get everything out to qt before trying to fix it.

 

[david40price]

I've tried Caleurpa in the sump doing just what you said, but it keeps getting shredded to bits. There is just to much flow through it due to the size of the pump. Do you think Chaeto would work better? It should tumble nice due to the water flow.

 

[jayball]

If you have a skimmer I would try a 3 day blackout (block any ambient light from nearby lamps, open windows, etc.). By the third day you should have to clean the skimmer cup multiple times a day so make day 2/3 is a weekend.

It is a great way to get some initial progress on the problem but as stated above make sure you do not have many settling zones where crap falls and the cyano scavenges it.

 

[lifeoffaith]

I'd build an algae scrubber instead of a skimmer. Lots of people have used them to replace a skimmer and they're pretty simple to use and build. Check out the Algae Scrubber thread for ideas. I'm still working on a larger setup so I haven't done it yet, but I've heard great things about them.