Bloom #2?

[JeffJ]

Hey Guys,

I'm having a 2nd diatom bloom (at least I think that is what it is...)in my tank and was wondering if you have any suggestions. I went through a bloom about 3 weeks ago and afterwards, the sand cleared up nicely. I increased the light time again (to about 12 hrs of act and 10 of wh) and did not see a noticeable change. Within the last week, the sand had gotten quite dirty again.

I'm attaching some pictures. As for a clean up crew, I have 3 Mexican Turbo Snails, many small snails (I would guess around 15 -- not longer than a dime each) and about 6 small crabs. When they first entered the tank, my crabs were extremely active on the sand, but now I rarely see them working on it. I see some activity on the rocks, but never really see them working the sand.

I do a 5% change every 1-2 weeks. I tested water today and had the following results:

PH=8.4
Ammonia =0
Nitrite = 0
Nitrate < 10 ppm (I really think it was 5ppm, but this is my first time to do this test on my own and I wanted to error on the high side)
SG=1.0225
Temp = 79

Thoughts?

 

[gmax]

Looks like a mild case of Cyanobacteria. Its a bacteria not an algea. Often this is a combination of high nutrients in the tank and low flow in the lower areas of the tank. Together the bacteria has a chance to take hold. You might try stirring the sand manually on the surface for a few days and trying to increase flow while be very careful about how much you feed the tank.

Good luck

 

[JeffJ]

Thanks Gary...is it potentially harmful? I thought it was more red in color...I'll give stirring a try.

Thanks!

 

[DaveJ]

You can also bump your salinity up to 1.025 or 1.026 and that will aid in knocking it down. Flow and nutrient export is your best bet. Its not that bad right now, but it can get thick and start to cover corals and such. Since you have a shallow bed, vaccuming the areas as you drain water for your changes should help. You might consider bumping that volume of change up to 20% for awhile until things disappear.

When you bump your salinity, do it slowly, like .01 per day. Using saltwater as your replenishment for evaporation is a good way to do it slowly. Just mix a 1/4 of salt into your evap water and you should be up in 3 or 4 days. Just keep an eye on it to make sure it doesn't go up too fast.

 

[bigtex52]

I would echo the cyano opinion. It's been my experience in the past that when diatoms have run their course that cyano seems to follow closely behind. Nassarius and cerith snails have always done a great job at working my sand over and keeping cyano knocked down.

 

[JeffJ]

Hey Guys,

I've been replenishing with salt water to try and get the salinity up as well as I've added 5 narcissa (sp?) snails. I'm not seeing a decrease, but it seems to be increasing. I've seen a small amount of growth on a couple of rocks. I also added 5 snails and 20 crabs two days ago -- when they entered the tank, the crabs went nuts eating the stuff (and knocked it down pretty good), but after several hours, they went belly up and I haven't seen them move again since...are the stuffed? (total of about 30 crabs and 10 snails in all).

What else can i do to help?

I have a Korilla 2 and 3 as well as a 300 GPH return on the system...is that enough flow, or do I need to add more? Also, I'm seeing bubbles on the surface (near the cyano) as well as a coat of green algae (very thin) on my glass each day. I've had a difficult time with temp flux, but I think the fans I purchased will help get that under control.

Had the water tested yesterday and these are the results:
PH = 8.1
Ammonia = 0
Nitrite = 0
Nitrate = 0
Phosphate = .25
Alkalinity = 2.5
DKh = 7.0

How concerned should I be and what additional steps do you think I should take. Thanks again!

 

[DaveJ]

@reefready wrote:

Hmmm belly up isn't good. Did you acclimate them slowly before adding them??

Now that we have a phosphate number, that is high, I would also like to know if you are using RO/DI or tap water? That number is about twice what it should be, if not more and could contribute to algae and cyno. You may also want to bump your alkalinity up a bit more, say to 8.0 or 8.5.

The bubbles you see are cyno, thats one of the signs of it. Your powerheads should be plenty for that size tank, just make sure they are flowing onto the sand, or across it. You don;'t want to stir the sand up, but you want a good flow over the surface of it.

The snails.. do you mean Nassarius snails??

 

[gmax]

I concur. The phosphates are your fertilizer, get them down and lots of nuisance growth stops.

Are you feeding flake food? Much of that is loaded with phosphate. How much and how often do you feed?

Do you have a refugium growing a macroalgae? It will also help export excess nutrients.

 

[JeffJ]

Thanks guys...

I'm feeding one flake of formula one food every other day and a third of a cube of frozen brine/myosis (you know what I mean even if I can't speeelll it) the opposite day.

I'm going to do a 5 gal change tonight and see if that helps. How else can I safely get the phosphates down quickly?

If you can see in the pictures, I have one powerhead in the front left and one in the back right, creating a circular type flow (in my mind at least)...is that good? Should I have them both in the front?

Thanks!

 

[DaveJ]

@reefready wrote:

That should be enough food for those little clowns and shouldn't be enough to start a large scale cyno break out.

Lets get back to your water, what kind of water are you using to mix salt? Are you using tap water? RO/DI? From some other source?

I'd put your PH's up in the upper corners aimed slightly downward. You don't want a race track, you want it to be all over the place (random) If you get it all going in one direction, it will just grow in that direction Have it with a back and forth or circular pattern and it will more easily break up.

 

[JeffJ]

Sorry...forgot to mention about the water. I'm buying my water from the LFS already mixed and topping of with RO/DI from the same store.

Let me make sure I get it, corners are fine, just move them up higher and angle them down more, correct?

Thanks again!

 

[DaveJ]

@reefready wrote:

Then your water should be fine, assuming they are keeping up on their filters. Yep on the Powerheads.. not a severe angle, but a slight one downward. You might also bounce the stream of one off the front of the glass to create a bit of cross current.