diatoms

[fishcrack]

I'm frustrated with the problem of diatoms. I'm pretty sure that's what it is since it's powdery brown in color and blows away with the turkey baster. I've religiously been doing water changes (20% in my 24 gallon nano each week), feeding every 2-3 days. I do have my lights on 9 hours a day because of corals but even before I added the corals, I still had the diatom problem. I've increased my cleaning crew (4 Mexican turbos, 4 nassarius, 10 astria snails, about 15 red and blue hermit crabs, 2 peppermint shrimp). I'm feeding a combination of mysis or pellets (New Life Spectrum - recommended by lfs) and occassionally Rod's Reef for the corals. I don't rinse the frozen. My levels last week were: nitrate 5, ammonia 0, calcium 400, ph 7.4. I can't remember my phosphate level but it was a normal reading. I'm due for a water change Monday. I also have a small spot of hair algae on one rock (strands about the diameter of a dime) that I keep pulling off by hand but regrows. My tank has been up since August. I know that a "new" tank has diatoms but should I still be having this issue. Does this mean my food quality is a problem? Corals and fish are all healthy but the diatoms look ugly! Oh, and I have a nano protein skimmer. I clean it every week but it does seem to put out a lot of micro bubbles. I've tried replacing the bubble pad. Experts??

[fijiwigi]

Have you tried checking your test results with another brand of test kit. Sometimes different kits can give different readings.
I had a diatom problem on my cheap petco bought sand that would not go away I added a better Caribsea aragonite sand and some macro algae Haven't had a problem since. Thats all I got good luck

[roka64]

Hmmm, if you have hair algae and your nitrates are at 5, I am thinking you have phosphates. I'm not quite sure on the constant diatoms. They usually burn out.
Do you have any foam or filter media?
What water are you using?

[Devilishturtles]

Diatoms can be frustrating. The way I understand the diatom lifecycle in our tanks is that they "bloom" during a cycle (new tanks for example) and as beneficial bacteria grow, they will go away. Once the amount of other bacteria is greater than those of the diatoms, they will not be able to survive. In my experience, as well as others on this board, they are there one day, gone the next.

Did the diatoms ever go away in the first place?

As much as I dislike reccomending this, try not cleaning the tank as often for a few weeks and see if that helps.

Edit: as FigiWigi said, silica sand MAY contribute to your problem. Diatoms are composed of silica and there has been some evidence that silica sand may contribute to them.

[fijiwigi]

could it possibaly be mistaken for cyanobacteria? A pic may help
The phospate test reading may be helpfull as well.

[melosu58]

Are you using tap water?

[fishcrack]

I use RO water filtered at home and Red Sea Coral Pro Salt that we mix at home. I'll recheck the phosphates on Monday (tank is at school). I'm fairly certain they were at 0 last week but can't say for certain (failing memory I guess). My son suggested I check the phosphates of both my tank water and the mixed water. Will the presence of diatoms give me a false reading on phosphates? Do diatoms feed off of phosphates in the same way that cyno feeds off of nitrates? I'm almost positive that it is not cyno - I've had that before. This is dusty like in appearance, whereas when I had the cyno I could peel if off my sand. I can't take a good picture - I've asked for a new digital camera for my bday next week so the picture will have to wait - sorry.

I have API test kits. I think they are pretty good?? Sand is argonite and is the same sand we have in our other sw tanks.

Could food quality be feeding the diatoms? I wanted to try macroalgae in my sump but there isn't enough light. Should I add it to my tank? If so, what kind and how do I keep it from overtaking the tank? I know you can trim it but I was concerned with space. I have 25-30 pounds of live rock in there too.

To answer DevilishTurtle - I didn't have this issue with diatoms before. Now that you mention it, it may have started to be a bigger problem when I started doing more consistent water changes. But, I ended up with the cyno because I made the classic beginner mistake of feeding every day. I didn't recognize cyno for what it was and it grew rapidly over a few days while I tried to research what kind of new "algae" I had. Then I got wise and started to read this forum more often. Since then, I have really being trying to be religious about water changes and feeding only 3 times per week. Should I wait on Monday's water change? Or test phosphates and go from there?

[fijiwigi]

Make sure you test your paramaters before the PWC at the end of the week. Do not test the tank water after a PWC it will dillute any Nitrates or Phospates that may have been there. Just a thought in case you are not doing this already. And is your filtered water just RO or is it RO/DI the DI resin will purify whatever the RO resin does not.

[fishcrack]

I have been testing after PWC - apparently another newbie goof. Another thing I've learned from you all. My water is RO/DI filtered. Sorry for the confusion. So, if I've been testing after water changes, all the info I've been getting could be wrong?

[fijiwigi]

Originally Posted by fishcrack

I have been testing after PWC - apparently another newbie goof. Another thing I've learned from you all. My water is RO/DI filtered. Sorry for the confusion. So, if I've been testing after water changes, all the info I've been getting could be wrong?

I would test your water before and after the PWC and see if there is a difference in the readings. And API are good reliable tests IMO> Is your phospate test API as well?