Help me out with algae control!

[fishcam]

I was reading on another thread about how to combat GHA and I've been following the directions:

 

I run 1cup of phosphate remover every two weeks along with a cup of carbon in two separate canister filters, I have a UV (whose bulb may be old), I siphon as much GHA out as I can at a time with bi-weekly 5g water changes (70g total volume), I replaced my 150W MH and 130W CF lights recently, and I am running new RODI filters from AWI. I have to admit, its getting better, but still... it grows!

 

Strangely, the GHA grows out of the way in the top rear corners of the tank, and the red (slime?) algae (which looks like a carpet on the sand and rocks its on) grows more or less under the direct MH light.

 

What else can be done to combat this?

 

The brand of my sterilizer evades me at the moment, but do UV bulbs have to be replaced annually too? Or are they good until they burn out so to speak?

 

I'd say its about time I replace my floss in the canister filters, but I've heard that only leads to nitrates if left unkept and I dont have a problem with those (less my test kit lie to me) but, I'll change those out tonight anyway when I'm adding new carbon and phosphate remover.

 

As far as I know (weekly high's and lows):

PH from 7.9-8.2 according to ACIII

CA ~380-420 (saliferts)

MG ~1250-1280

ALK ~7-9 (this is a tough one for me to keep high, so this week I dosed to 10 and I'll see where it is at the end of the week- hopefully 8)

 

the nitrates and nitrites should be zero, but I'm not using salifert tests for those.

 

What else can I do?!

 

Thanks!

[Brian Ward]

your nitrates can read zero if they are being produced and consumed (by the algae) at the same rate. so you probably have some nitrates coming from somewhere - the filter floss in the canister is a good candidate.

Sounds like you have some areas of low flow that is allowing the GHA to grow - that coupled with the probably nitrate source could be part of your problem. the red mat is cyano. virtually the same things that feed the gha feed cyano. get your nitrates sources neutralized. what other physical filtration do you use? filter socks? sponge? make sure these are changed regularly. decaying organic material trapped in these will create nitrates. are you siphoning detritus from any low-flow areas?

UV bulbs must be replaced about every 6-9 mos just like CF bulbs. They lose their intensity and thus lose their effectiveness. make sure you're flow rate through the UV isn't too high - if you don't have enough exposure time you won't be killing anything with it.

vodka dosing is another way to get rid of nitrates. if you choose to go this route, you will need a highly accurate syringe and a log book. link to the instructions is below.

for your water changes - is that 5 gal every other week or 5 gal twice a week? I would be changing a minimum of 10 gal every week and 10 gal twice a week wouldn't hurt just to be sure you are getting rid of the nitrates. as the nitrates are removed from the tank, you will see the HA begin to die off.

 

Vodka dosing: http://www.reefkeeping.com/issues/2008-08/nftt/index.php

[MisterTang]

Brian,

 

This is an interesting idea... I hadn't considered a "net zero" scenario in my nitrate levels, and had rather been pretty happy that I was getting 0 nitrates! I am interested in trying the vodka dosing method, but how am I supposed to calculate a stable maintenance dose when my nitrates already read 0 (presumably because the nitrates are feeding the algae)?

[fishcam]

your nitrates can read zero if they are being produced and consumed (by the algae) at the same rate. so you probably have some nitrates coming from somewhere - the filter floss in the canister is a good candidate.

Sounds like you have some areas of low flow that is allowing the GHA to grow - that coupled with the probably nitrate source could be part of your problem. the red mat is cyano. virtually the same things that feed the gha feed cyano. get your nitrates sources neutralized. what other physical filtration do you use? filter socks? sponge? make sure these are changed regularly. decaying organic material trapped in these will create nitrates. are you siphoning detritus from any low-flow areas?

UV bulbs must be replaced about every 6-9 mos just like CF bulbs. They lose their intensity and thus lose their effectiveness. make sure you're flow rate through the UV isn't too high - if you don't have enough exposure time you won't be killing anything with it.

vodka dosing is another way to get rid of nitrates. if you choose to go this route, you will need a highly accurate syringe and a log book. link to the instructions is below.

for your water changes - is that 5 gal every other week or 5 gal twice a week? I would be changing a minimum of 10 gal every week and 10 gal twice a week wouldn't hurt just to be sure you are getting rid of the nitrates. as the nitrates are removed from the tank, you will see the HA begin to die off.

 

Vodka dosing: http://www.reefkeeping.com/issues/2008-08/nftt/index.php

 

Interesting Brian Thanks. I'll try the everything but vodka for a while and see if that takes care of it. I do have some flow issues... but nothing I thought was too serious... perhaps it is!

 

Thanks

[Brian Ward]

Brian,

 

This is an interesting idea... I hadn't considered a "net zero" scenario in my nitrate levels, and had rather been pretty happy that I was getting 0 nitrates! I am interested in trying the vodka dosing method, but how am I supposed to calculate a stable maintenance dose when my nitrates already read 0 (presumably because the nitrates are feeding the algae)?

 

Calculating the final maintenance dose i haven't really figured out yet. My thought (disclaimer: these are my thoughts based on my understanding of how the dosing works, as well as my conversations with Josh (yauger)

 

My thought is that in your case, go with the minimum dose and see if that causes your algae to die out. If not, double after a week. Go slow and the algae should die out eventually - once you see signs of dieoff or at least the growth stopping, maintain that dose - that will indicate that you have grown enough bacteria that it is consuming the nitrates before the plant matter can. Then you can cut in half - see if that causes nitrates to increase. In the short term, the algae won't grow back fast enough to consume the nitrates so you should see a slight increase in your tests - but you'll need daily tests. If the nitrates don't increase, you're good. If they do, then increase your dosing slightly. The key is to go VERY SLOW. In your case especially, a dissolved oxygen test wouldn't be a bad idea to be sure you don't end up with a bacteria bloom that consumes all the oxygen.