Diatoms and Cyanobacteria help

I need some help. I have been battling both diatoms and cyanobacteria for a couple months now. Tank is relatively new yet (I think around 8 months). It is a 90 gal DT, 10 gal Fuge and 10 gal sump. My Fuge is also covered in Cyano which is choking out my macro algaes, so every once in a while I turn the lights out for a couple days and let it die back a bit but once I turn the light back on, it spreads like crazy again. In the display tank it seems to grow mainly in the bottom left corner (which is low-flow and I haven't been very successful in increasing flow without stirring up the sand bed), but is also in other areas as well but not as heavy as the bottom left corner.

In January I switched from tap water to RO/DI water thinking that was the cause of the diatoms, and it did help significantly but I still get a dusting on the glass that needs cleaning maybe every 4-5 days or so.

I feed the tank once a day, mostly frozen mysis or brine shrimp, so I don't think I am over feeding.

My params are as follows:

Nitrate: 10ppm
Nitrite: 0
Phosphate: .5ppm (I think, it was the first color on the chart)
Calc: 280
Temp: 79
PH: 8.1

I am basically looking for some type of list of causes and solutions relating to these 2 "algaes" so that I can go down the list and try each solution to see if it helps.

In regards to the fuge - Is there anything I can do to stop the Cyano from growing in there being that I am basically providing an ideal environment for it to grow (Low flow, 18 hrs of light)?

Any help is appreciated.

 

That BAD green stuff

Speaking as an old time newbe You might try a UV light filter. There are chemicals that say they can handle that problem but UV would be my choice. Maybe some of the long on expertise members will weigh in.

Rick

 

There is nothing you can do about the diatoms, they will disappear once all the silicates are used up in the tank. As for cyano, if it's starting in one spot, add some flow there, keep stuff from settling out. There may be residual po4 and junk from before you switched water sources. Keep up with manual removal of the cyano. Also I would let the cyano live in the fuge, it will help keep it out of the DT. If you do do a lights out in the fuge, you need to manually remove as much cyano as you can first, because when it dies, it releases all the po4 and nitrates its eating back into the water, defeating the purpose really.

 

That's interesting, I've been doing the lights off thing for 4 days now and it's almost completely gone so I guess I'll just let it continue until I don't see any signs of it left, but I'll keep this in mind for the next time it comes back.

So are you saying that it is okay that the Cyano is choking out the macro algae?

 

I have little outbreaks of cyano here and there too. nothing too big but I'll get a spot or 2 on the sand maybe silver dollar sized or less. I was wondering if a sand sifting goby would go after this as a food source. any thoughts? Also what the heck does IMO stand for?

 

Well, I've never tested my ph, but,

Why are your nitrates 10? Phos should be 0 also, on an ATI kit anyway. I know there are more sensative ones.
Ca of 280? Mines like 500, and I don't dose a thing!
Do you have any corals? What salt mix do you use? What do you keep your SG at?
18hrs of light on the fuge? I run a 5100K standard CFL bulb only 12hrs in a funnel like reflector over my chaeto basket in my sump, and the chaeto grows like crazy!

I agree with trying the lights off for about 4 days, and doing several water changes. MOst salt mixes get your Ca up to about 450-500 @ an SG of 1.025ish.
I keep my tank @ .026-.027ish

I'm not attempting to be critical of you or your system at all, I"m just throwing some things out there that may help.
My tank is only about 9mos old also.

 

Dusting on glass is normal. When I add GFO reactor, I have not see any cyano or any diatom.

 

I don't know why my nitrates are 10ppm...I have never been able to get them lower then that.

I actually just bought the API test kit this week because I wanted to test for Ca and Phosphates, so I just found out my Ca was low and had phosphates. I was using those dip stick tests previously that didn't have those 2 tests on it.

As for corals, I only have 3 frags, 2 leathers and a zoa, that I just bought maybe a month ago, I am converting to a reef system very slowly and am getting my feet wet with softies.

The salt mix I use is Instant Ocean...I know it isn't ideal for a reef system but I don't want to waste the half a box I still have, so I will continue using it until I run out and then will buy better salt mix.

I run a 6500k bulb with the metal reflector cone on the fuge and run it opposite of the daylights (which are only on 6 hrs/day, I run the actinics for 8 hrs/day as well). The macro algaes grow like crazy too but eventually the cyano completely covers everything and then it seems as tho the growth stops.

I keep my SG at 1.024

I think that covers all of your questions.

 

IMO = In my opinion

Most of my cyano is on the live rock but I actually did have a sand sifting goby for a couple months during the early months but he eventually died, not exactly sure why but I am assuming it was because he wasn't getting enough food. I also learned along the way that gobies are meat eaters and cannot survive solely from the nutrients in the sand bed. And while my goby did eat mysis shrimp, he may not have been getting enough of it and eventually starved to death.

 

What is a GFO Reactor?