The thought process behind incorporating an ATS into your reef aquarium is two-fold.
2) To provide nutrient export by harvesting fast-growing turf algae (Raabe 2008)
Turf algae grows well in the areas of the reef tank where there is high oxygen/ gas exchange. The system described here is a simple Perspex or glass screen over which water is allowed to flow within a portion of the sump. This provides a perfect environment for the turf algae to grow.
When designing my sump I had in mind that I would be incorporating an ATS from the start, but this can also be achieved within an existing sump arrangement by diverting some of the overflow over a screen or plate before entering the sump. Another way to provide a good habitat is to lower the water level in the last compartment of a sump so that the water flows down a vertical glass pane.
I had the sump designed as two sections, primarily because it was to replace an existing arrangement and this was the only way that I could get a large sump into my cabinet.
Seen below, the first section of the sump has one end lower than the rest. The water overflows from this end, over the glass pane (ATS) and into the second section.
The picture below shows the second section, with
the overflow part of the first section shown on the right. As you can
see, fixed to the first baffle in the middle is a thick piece of glass.
The ATS pane is designed to be removable, it rests on the top brace to
the right, and this thick piece of glass to the left. Water is designed
to flow over it and into the compartment
This picture shows the same section after
installation underneath my tank. I have not yet put the screen in
place, the water is simply flowing from the right hand section into the
left in this picture.
This is the Perspex sheet intended as the screen.
The bars across were for strengthening. I have since replaced the
Perspex sheet for a glass pane, as I found that even with the bars,
once a good growth of algae was on it the Perspex started to
The sheet is placed on the right hand brace and
the supporting bar on the baffle to the left. Water flows over the
sheet and into the section underneath.
Some turf algae from my reef tank is placed on the screen and temporarily held in place by some flexible tubing to ‘seed’ the ATS. It takes a week or so for the turf algae to get a decent hold and the tubing is removed. As you can see, diatoms are starting to build up on the ATS after only a couple of days.
This is two months later, just before I cropped
the ATS for the second time. As you can see, the turf algae has nearly
completely covered the screen. Lighting over the ATS is two 15w normal
output marine white fluorescent tubes. There are two Compact
fluorescent marine white bulbs (36W) lighting the other side of the
section over the Chaetomorpha. Some of the light from these would also
be utilised by the turf algae.
It would be interesting to analyse the algae and the detritus held within with a microscope to see what life there is living there. Since I do not have such equipment yet I have made do with a magnifying glass. So far I have identified copepods, amphipods, isopods and various worms, mostly of the ‘bristle’ variety. I am glad that I married my wife before she caught me looking at algae through a magnifying glass, her face when I was ‘caught in the act’ spoke volumes!
Other changes were made (installation of RDSB, addition of live rock section and increased water volume) to my sump/ refugium arrangements at the same time as the incorporation of the ATS. Because of this I am unable to say how much difference just the incorporation of the ATS has made. Since making these changes to my reef tank, however, the system as a whole has benefited with increased growth of Scleractinian corals and general excellent health of inhabitants including fishes.
Nitrates in the system have been reduced from about 5ppm average to just a readable trace since the efficiency changes. Phosphates are easier to control and keep at the lower end of the scale (0.001 – 0.003ppm). Chaetomorpha was already being grown, so the combination of increased water volume, RDSB (Remote Deep Sand Bed) and ATS must be responsible for this. The aim was never to reduce these parameters to zero as both are necessary nutrients. They do, however, occasionally show up zero - if this happens then the feeding is increased. I am now able to feed the system more frequently, and have added an automatic feeder to provide dried food throughout the day.
When the turf algae is cropped or disturbed – sending the cloud of brown detritus collected by the algae (with whatever else is in there) into the water stream - coral polyp extension is seen to be exaggerated on certain corals (Hydnophora, Goniopora, Merulina and Galaxia particularly). This evidence is purely anecdotal. It would be interesting to see if another system/s benefit with just the addition of the ATS and no other changes.
As we all know, space is at a premium in most reef tanks, and inside the cabinet itself is no exception. The ATS makes a fine addition to a fishless refugium design, while taking up very little of the valuable real estate underneath the tank.
Raabe, C (2008) A Philippine Fringing Reef & The Reef Aquarium http://www.chucksaddiction.com/articles.html
Article Submission, Algal Turf Scrubbers 12/30/08 Hi Crew, <Simon> I have been encouraged to write an article about a recent DIY project that I have undertaken on my reef tank, and further encouraged to send it on yourselves. It is a simple ATS built into my sump. <It's excellent!> The article is in two parts because of the size (due to the photo's). I would appreciate any comments/ criticisms/ improvements if nothing else would be great. If you wish to publish in CMA then I would be honoured and require no payment. <I insist that we send along the pittance for this excellent work... am issuing through PayPal to your email address here> Quick Bio: I kept Cichlids for 18 years before I moved onto marines 6 years ago, first of all fish only, graduating onto reef over time. My current set up is a 180 gallon reef, stony coral dominated. I have 3 QT tanks in the loft that I use religiously. I recently had my only ever major disaster when a power shortage flipped the switch on my house while I was away, with no power for just over 24hrs all my fish and Acropora died. All other corals were fine. Have since spent a small fortune on batteries etc. I currently help out on the 'about saltwater' forum, but have been unable to access it recently as my modem is down at home. Will be back on helping out asap. My username on there is 'Eddy' (my middle name!). Thanks very much, Simon Trippick <Outstanding! Should you find yourself with "extra" time, would you consider helping respond to queries here on WWM? I do think that others would benefit from your experience, relating. Bob Fenner>
Re: WWM Article Submission 12/30/08 Thank you very
much Bob, very much appreciated, more so the positive comments! My wife
now (at long last!) appreciates the true value of algae as well - as in
she can now have that new pair of boots she wanted!! <Hah~!> I
did not get the confirmation back for the second part of the article,
did you receive it? <Yes... will be posting both/together in a short
while... on WWM> I would love to become a member of the crew, and I
really appreciate the offer, but I will have to decline it as I would
not want to let anyone down. I believe an hour or so a day is too much
for me to commit to at the moment, which I believe is what is probably
required, especially with the 'about' forum as well that I
already have commitments with. <I do understand... and instead will
look forward to a time when you feel more you have more time to share
with us> I am likely to become a house-husband in a couple of years
time, and will have a lot more experience then as well as I intend to
do a large-scale tank build. I would be more than glad to help out then
when I can be sure that I can put in the time required. <Ah,
good> Thanks again for your comments and help in the past also! Some
of the payment will be going towards the person who has guided me most
- he's a great guy called Charles Raabe who lives in the
Philippines and has just had a heart attack and now has a massive bill
to pay. He's the one who encouraged me to make the changes in the
first place, write the article and send it to you as well, so I think
it's only fair that I repay him when he needs it most. Thanks
again, Simon Trippick <Again, you are inspiring me, and helping many
others through your efforts. I thank you. Bob Fenner>