Kill brown water with UV

After 20 years in the reef keeping hobby, I was about to call it quits.  My 90 gallon reef tank, setup since 2000, was giving me a problem that I couldn’t fix.  The problem you ask, was brown water.  Water so brown that I couldn’t see my fish unless they swam near the front glass and I wasn’t sure if my rock was still in the tank.

A little history first

Around February of this year, I replaced the single Current USA Orbit Marine IC pro light with two VIPARSPECTRA 165 watt led fixtures.  My corals basically stopped growing after I installed the Current USA light and a single Current USA light wasn’t enough for a 24 inch tall tank.  Even though it looked great, I needed something brighter.

The VIPARSPECTRA’s are much brighter in comparison and I was getting ready to start adding corals again around April but I noticed an increase of brown algae growth that looked much like cyano.  I didn’t think too much about it but it started to get progressively worse as time went on and around June the water was brown after the first couple hours that the lights were on. 

Water changes didn’t fix it

Around the second week of August, I started changing water.  I would normally change around six gallons at a time in the past but this time, I did an 18 gallon water change.  The water looked better the next day for about six hours but then it started to turn brown again.  Thinking that the water change might have helped, the following weekend I did another 18 gallon water change but it only a lasted a couple hours after the lights came on the next day.  The third week, I did one more 18 gallon change and the next day the tank water was brown after about an hour when the lights came on and it got progressively worse over the following week. 

I am guessing that the nutrients in the clean salt water was feeding what ever was causing the brown water.  I couldn’t do more than an 18 gallon water change with my current setup and I concerned that anything bigger might cause issues for my 20 year old clown fish and my 11 year old powder blue tang.

Then the (UV) light bulb came on

Many years ago, not long after I started this tank, I installed a UV sterilizer.  I didn’t have a problem at the time when I installed it but I was all about the technology back then.  After a couple years of using it, I took it off because I wasn’t able to clean the sleeve inside.  I cannot say that it helped or not but I didn’t really think much about it for many years since then.  

I started looking on the reef keeping forums for brown water in salt water tanks and saw a couple comments about some others suggesting a UV sterilizer to battle brown water.  I didn’t want to buy a new unit just going on a hunch but since there were at least a couple other people suggesting it, I ordered a unit from Amazon.  

The unit I ordered was a 15 watt Aqua Ultraviolet Advantage 2000+.  I was a little disappointed when it arrived because I realized that I paid $130 for a little plastic tube with a power supply and bulb but I had to give it a chance or send it back and consider my exit plan from the hobby. 

It wasn’t the easiest to plumb in my already tight stand and sump but with $20 in vinyl tubing, a Maxi Jet 1200 and some various plumbing parts, I installed it last night.  I didn’t expect to see any improvement in the few hours that my lights were still on but I was hoping that I would see some improvement in a few days to a couple weeks.  

What a difference a day makes

Today, when the lights came on, the water looked better than it has over the last few months but I was waiting for it to turn.  My wife told me, that about two hours after the lights come on is when the water would change to brown.  Today, after four hours, the water was not brown.  After six hours, it was still not brown and as I type this, after nine hours, the water is still not brown. 

I never would have thought that within 24 hours, the UV would have worked enough to allow me to see in my tank after months of brown water.  I am not sure how well it will work long term but it’s looking better after only one day. Needless to say, I am pretty impressed and I will update this post to see if it keeps the brown water away.

Brown water on 9/02/18

Could hardly see my fish

not brown water

24 hours after UV on 9/03/18





Don’t let a power outage kill your reef aquarium

Here in the midwest, I am not a stranger to power outages.  From thunderstorms, to tornadoes, to the electric company just not doing their job, to solar flares that threaten our power grids, I have had many power outages over the years since I have been keeping my aquariums.

Many years ago, around the summer of 1998, I lost a couple corals after an extended power outage and because of that I purchased a portable generator.  The generator worked well for the power outages that followed but it is not the easiest unit to use and for short outages, under eight hours, the time to get it hooked up and working isn’t worth it.

I was searching for a simple solution that I could easily hook up, didn’t need gas, has enough power to run a single pump in my aquarium for at least eight hours and didn’t cost a lot of money.

Sometimes simple is better

I had purchased a portable 12 volt auto battery starter a few years ago that is used to jump start cars and power small 12 volt devices.  This unit has a 12 volt receptacle for connecting the devices.  The unit that I use is at least six years old now and it is a Husky brand 400 amp battery jump starter.  There is a new unit available from Stanley Tools at Lowes but it is only a 300 amp (not an affiliate link) unit which may or may not be an issue and I assume would not have as much runtime as my device and you should make sure that you can return it if it doesn’t work for you.

I also use a Husky brand 175 watt power inverter which is no longer available but there is a 180 watt (not an affiliate link) unit from Energizer that looks similar to mine.  This unit plugs into the 12 volt receptacle on the jump starter and it has a single 120 volt outlet.  The pump plugs into the 120 volt outlet on the inverter.  There’s no need to do any type of special wiring, you just plug it in and it works.

 This is not an automatic backup that turns on when the power goes out but if you have someone at home, they can hook it up in a matter of minutes without any other skills than plugging the pump into the inverter.

It keeps the water flowing

I am using a fairly large Tunze pump which yields just over eight hours of run time with the above setup.  I had to use this setup recently after a large storm took out my power for just over six hours.

I have tested this same setup with my Mag 9 pump but it makes the pump chatter and I didn’t want to damage it.  I am assume that the Mag pump draws more than 175 watts so that might be the cause of the chatter.  The Tunze pump is silent until the battery runs down and it will start to make a slight chatter.  Just make sure to choose a pump of a lower wattage than what the power inverter outputs.

It haven’t tried this setup with a heater because I am guessing that the 200 watt heater I am using would drain the battery really fast.  I am going to test this out in the near future to see if it works and I will update this article once I have more information.

Low cost solution to short term reef aquarium saving power

The parts that I listed above cost about $110 USD from Lowes and I would assume that you might be able to find them online for less.  This seems like a small price to pay to save our fish and corals and the many thousands of dollars that many of us have invested in our aquariums.

Leave me a comment below if you use this type of setup and how it works for you.