I would like some help to try to figure what type of algae this is and how to defeat I have been battling this for the last month, but it has getting worse in the last week. My tank is 90 gallon with a sump, AquaUV 15 watt sterilizer on it, 8 months old. Phosphate for the last month .13 to .3 I know this did not help. Currently only have blue and uv on 2 xr30 gen 3 running at 20 percent overall brightness. 10% water change every week. I have been dosing brightwell microbacter clean over the last month it use to help but not some much any more.
Water parameters
Alk 9 dkh
Salinity 1.025
Calcium 450 ppm
Phosphate .003 ppm currently
Nitrate 10
Mag. 1350 ppm
Nitrite 0
Rodi water 004 ppm
Any help and course of action would be great, ty.
Diatoms. While many call it normal although to a degree it is, it has a cause. Is it bad- No . . . Just unsightly.
Diatoms are a brown algae that typically appear in a reef tank that has just completed its cycle but they can also appear in an established reef tank. They can cover sand, rock, pumps, glass, you name it. Diatoms look ugly but in most cases they are harmless so the key is to not panic when they appear.
Diatoms feed mainly off of silicates but also consume dissolved organic compounds, phosphate and nitrates. Unfiltered tap water can contain silicates and is a good way to jump start a bloom if you use it to mix salt or to replace water that evaporated from the tank. The best way to prevent this from happening is to filter water through a RODI unit, although you can still get a diatom bloom when using RODI if the cartridge that removes silicates expires.
diatoms are typically harmless to a captive reef and can be beaten once their food source expires. Once you put the kibosh on the source, the outbreak should last a couple of weeks so just be patient and it will pass.
For major outbreaks you may want to consider the 3 blackout. Diatoms are easily wiped from the glass with a mag float, a turkey baster or a toothbrush can access other areas of the tank. Be prepared for them to re-establish themselves quickly, they are likely to be able to resettle and have exponential growth rates.
To prevent their return, practice good aquarium husbandry by doing regular water changes, keep the substrate clean, don’t overfeed the fish, ensure your skimmer is running at an optimal level and rinse out filter socks and sponges on a regular basis.
Some cleaner crew to help control it are : Cerith snails, Nerite snails and Trochus snails and also Astraea snails are effective at removing diatoms.
