66g reef tank, no coral yet just a bunch of trochus, astrea, cerith, and 2 small tiger conchs and 2 red blood shrimp and 1McCoskers wrasse and Rainford's goby. Tanks been running since last October. Used dry life rock to start with a couple of inches of caribsea arag-alive ( thoroughly rinsed b4 adding to tank). Cycled by January, no algae problems until about 3 months ago started getting diatoms on sand in front and sides. At that time NH3 0, NO2 0, NO3 2-3ppm. PO4 0.09, Si ~0.5. Light feeding of fish. Weekly W/C of 20% , have a HOB Aquamaxx 1.5 skimmer hooked up to a BRS CO2 scrubber. For flow using 2 Nero 5 wave pumps at each end of tank, Random mode, antisync, Max flow - 67%, Min - 34% *Will be replacing them with 2 Maxspect xf330's in next 2 weeks . CUC only made a dent in diatoms. Forward to 3 weeks ago along with W/C removed top layer of sand that had the diatoms - kinda sticky stuff - and replaced with new arag-alive rinsed in RO/DI. Diatoms not present for week or so then last 8 days started coming back. Tonight checked parameters : Alk 7.1 , NO3 <1ppm ( Nyos test kit), PO4 = 53pbb = 0.053ppm (Hanna checker), Si = 0.03ppm ( Salifert). S.G = 1.025. Why is this stuff coming back? I know if u have silicates that can be a problem but at 0.03 really??!! * I use every 2 weeks Probido Bioclean bacteria - supposed to gobble up NH3, NO2, No3 and sems to be doing a very good job. *FTM using media reactor containing ROX carbon & Phosban. But since PO4 is very low I switched phosban & carbon with Chemipure Blue tonight. Lighting is an AP700 running at 34%, 18K for 6 hrs. with 1hr ramp up/down using ~20K.
**NEED HELP : still having problem with diatoms
- Thread starter Johnny M
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Don't know what tap contains, never tested it. Have a 5 stage rodi unit from brs. Recently changed the sentiment & di resin cartridge - only got unit last October when I setup tank. Have a tds meter that came with unit that shows b4 it goes thru di final stage, 1-2ppm. After di -0ppm
Using Hanna checker for phosphate ulr.
sixty_reefer
5000 Club Member
2 second video & pics
Did you add new sand recently? The bottom layer seems more fine that the top layer.
Actually it is the opposite. About 2 weeks ago I scooped up the top layer of sand where the diatoms were - sticky stuff - and replaced with less fine and more coarse arag-alive sand, along with a 20% wc. ( using Tropic-marin classic salt ) , B4 adding thoroughly rinsed sand in rodi water. Within a few days the diatoms started coming back.
as stated in initial thread : Lighting is an AP700 running at 34%, 18K for 6 hrs. with 1hr ramp up/down using ~20K. I originally had for several months lighting period 16000K for 9 hrs. @ 40% with 1.5 hrs ramp up/down 18-20K and no algae problems until diatoms started, that's why i cut back to above schedule. I should add light is ~7" off water surface and another 16" to bottom sand. *Also note no diatoms on rockwork just bottom sand.
Is 6 hrs. @ 34% still too much? I have a par meter I bought from BRS -
Apogee
MQ-510 FULL SPECTRUM UNDERWATER LED PAR METER, coming soon so i'll check it.
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Magellan
2500 Club Member
The live sand seems to be a nutrient source for the diatoms, I just had to wait it out. By putting more live sand in there you may have reset the clock so to speak. Also, what are you feeding your fish?
IMO not really "live sand". When added originally rinsed it thoroughly with rodi water till it ran clear and also the top off a few weeks ago same so i don't think there was any live bacteria left. As for feedings : afternoon - 2 pinches of Sustainable Aquatics Dry Hatchery Diet pellets, .8mm slow sinking pellets. In pm one pinch of same pellets mixed in with a 1/2 cube of Hikari frozen brine shrimp infused with omega 3 fatty acid and selco boost ( 1 pump) in ~ 2oz. of rodi water. Don't even add the whole pm feedings if it can't be eaten in a few minutes.
Magellan
2500 Club Member
The pellets are packed full of nutrients that aren’t easily exported from the tank. I had more success when I mixed in a good quality flake food (I use omega one marine flakes with garlic) that I crush up in my fingers to make it easier for the fish to eat (my cleaner shrimp loves it too!). I turn the flow off, then anything that doesn’t get eaten will immediately end up in the overflow when I turn the pumps back on. I will still put some pellets in there as well, but proportionally much less. In addition, half a cube a day seems like quite a lot for such a small bio load, I mix in some frozen mysis for my fish/corals and a little bit goes a long way!
If it were me, I would add a few more fish, perhaps a tuxedo urchin or two, feed them less, and potentially add some extra biological filtration as well (I use Matrix and MarinePure Biofilter media).
If it were me, I would add a few more fish, perhaps a tuxedo urchin or two, feed them less, and potentially add some extra biological filtration as well (I use Matrix and MarinePure Biofilter media).
Thanks for the advice. I tried several types of flake but the wrasse & goby will only eat the pellets & shrimp
I have a bangaii cardinal & forktail blenny ready to come out of qt into DT & those 2 will not eat flake foods either. I tried a tuxedo urchin several months ago when I had several tufts of brown hair algae. After he ate that up there wasn't much of any kind of algae left & he eventually starved. My cuc is 2- tiger conch's, 7- astrea, 8- trochus, 6- nassarius , and 7 ( large) cerith snails. I'll try feeding a little less & maybe turn down the intensity of the ap700 from 34% to 25% for 6 peak hours, since I don't have any coral yet. Do u really think I need more snails? Should I try a tuxedo urchin again and maybe feed him nori, because once the diatoms are (hopefully ) gone there won't be much food for cuc. **if u think I'm overfeeding why would my NO3 be less than 1ppm and PO4 0.03? **FTM I have several Marine pure cubes in rear sump since tank was started. Plus appear to be getting nice dark skimmate in my Aquamaxx hob 1.5 skimmer so I know it's pulling out a lot of junk.
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sixty_reefer
5000 Club Member
I would strongly suggest you to observe it under the microscope, there’s a big chance you got a mix of dinoflagellates and diatoms. There’s also a test that can be done with a clear glass and kitchen towels to identify the dinoflagellates
If you can use this internet forum, and pay for an aquarium, you have access to a microscope. Buy one off amazon for $10-20. It seems to me your tanks is immature and under stocked for how old it is, I wouldn't worry about a small amount of diatoms. Add more fish and feed more I would also feed frozen but that's just preference. If you aren't dealing with dinos add corals.
I got out of the hobby for 10 years, got back in 6 months ago. My brand new tank had corals and fish in it a month after setup, and sps after 2.5 months.
