What are we doing wrong??

[hOOPSNAKE]

Hi All,
I'm hoping you can give us some answers as to why our algae scrubber is not doing .. well .. anything.

We have a 300lt + sump tank with 2 LED radion lights hung at 8 inches from water surface running at 100% intensity. There are currently only 3 live fish, a Tang and 2 Ocellaris who breed regularly, 3 Peppermint shrimp, 1 Strombus snail, a couple of surviving snails, 1 very annoying elusive mantis shrimp and even nastier mollusc eating worm.. Not a lot in there as we want to first get the algae and pesky hitchhickers out.

Anyway, we tried to tackle the algae with the algae scrubber, that was back in early December, it is now April and the algae is just getting worse.
The light of the algae scrubber was on 18 hours a day at first but didn’t get full coverage of plastic mesh, after lurking on the site and reading as much as I could I then cut the hours back to 8 to allow even growth. The algae never grows completely over the mesh, there is always a spot in the middle that remains clear (see photo).

Any advice would be welcome as my partner is wanting to throw it out and go back to a conventional refugium.

http://i1049.photobucket.com/albums/s385/TiffnMatt/DSC00233_resize.jpg
http://i1049.photobucket.com/albums/s385/TiffnMatt/DSC00234_resize.jpg
http://i1049.photobucket.com/albums/s385/TiffnMatt/DSC00235_resize.jpg
http://i1049.photobucket.com/albums/s385/TiffnMatt/DSC00238_resize.jpg

[Devs]

I'm sure SM will help you out better than I can, but just so he has a little more info....

How long are you letting the screen go before each clean ?

How much air flow do you have ?

[Garf]

Your skimmer looks dry in the pics. Are you running it, or activated carbon? What nitrate and phos you got? What's pH and ALK?

[kotlec]

Can it be your scrubber is way too small ?

[SantaMonica]

Welcome.

Two things; first, just let the screen grow 14 or 21 days. It will fill in at some point. More air bubbles will always help, but it's growing good now. You might cut 2 hours for a bit, which will help too until it fills in.

Second, although you probably are not feeding much, you have a huge amount of P stored in the rocks. It probably is starting to come out which would explain the increase of nuisance growth, although I'm not sure it's from the scrubber since that's not much scrubber growth compared to the stored P. However in general, the faster the P comes out of the rocks, the more nuisance algae will grow for a while until the P gets used up. On the plus side, your water P is probably very low and in good quality.

The main issue, after you let the screen grow more and get thicker, is that even if the screen is fully packed it's really too small for the amount of stored P. The scrubber does not know you are only feeding a little bit; it only knows that it seems to have an unending supply of P coming to it, which of course is coming from the rocks. At best it would take a few years to pull all of the P out.

So you are going to need additional P removal in some fashion. Larger or additional scrubbers is an obvious way; the more the better, for the first year. However you may also try GFO, and/or arbon dosing plus a working skimmer. If it were me, I'd empty out the sump entirely all the way down to the bare walls so that water has an open path from one end to the other, and then just add more scrubbing power. 10 cubes of scrubbing power could probably get the P out and clean the rocks in 6 months, without waterchanges or any other fiters. 5 cubes of scrubbing power could do it in a year. Stronger scrubbing + GFO + carbon dosing + waterchanges would be the fastest but of course the most work. Your sump's best and cheapest option is probably to remove the skimmer and make a waterfall scrubber from the drain, being as large as can fit in the left section, and with a light of 2 watts per square inch on both sides, and then add an HOG1 next to the HOG.5. After 6 months or so the waterfall will not be growing as thick, so you can remove it and have an open left section. Then after another 6 months, you can probably go down to just one HOG.

Once you get the P out, then the one HOG will suffice.

[hOOPSNAKE]

Hi guys,
Yes the skimmer is turned off in that picture due to just being emptied, it is usually going though. The air pump to the scrubber is for a 30ltr tank and bubbles quite well. We have let the screen go for months without cleaning, never gets overgrown, always the clear spot in the middle, meanwhile we clean the water return outlets of algae once a week! You could be onto something about the P in the rock, we have had the tank set up for a year, not much bioload, not overfeeding them, and we still have a P reading of 0.08 which is the lowest it has ever been. So it has to be coming from somewhere. Nitrates and Nitrites and ammonia are all 0, and we have a Two little Fishies PhosBan Reactor150™ which has been going now for about 7 months, have topped it up twice in that time.
However still not sure why the algae is not growing in the scrubber when it is growing everywhere else. Any thoughts?

[Rumpy Pumpy]

However still not sure why the algae is not growing in the scrubber when it is growing everywhere else. Any thoughts?


Maybe because the sheer volume of algae growing elsewhere is using up the nutrients before it gets to the scrubber?

I'd pull some of it out by hand or get something to eat it. A big sea hare or a dozen or more turbo snails.

[cdm2012]

We have let the screen go for months without cleaning, never gets overgrown

You need to clean the algae screen on a regular basis, usually every 14 to 21 days, religiously. Algae is consuming nutrients and then needs to be exported out of the system. You run the risk of re-releasing those nutrients back into your system. So, clean your screen regularly and do as Rumpy Pumpy recommended, manually remove the display algae. It will probably grow back to some degree, but if you get into the habit of doing the cleaning of the screen regularly and removing the display algae as best as you can without disturbing your rocks and substrate you should overtime see a huge improvement.

[cdm2012]

Is your air-hose clogged up algae? It looks like algae growing inside the hose.
4202

[SantaMonica]

That's just how the hose looks after a while. More bubbles never hurt though.

Your tank is one of the hardest situations, when it has a huge scrubber in the display. You can pull some algae off the rocks, but not too much too soon or the P will shoot up in the water and cause black scrubber growth. Also you can reduce the display light hours.

Go ahead and clean the scrubber.

[hOOPSNAKE]

Hi Rumpy, the algae scrubber light is on overnight, so I don't know that there wouldn't be enough nutrients in the water, and obviously, from the level of algae there is a heap to go around. What we didn't mention in our opening post, and should have to give you the fuller picture is that we do do water changes and manual removal of existing algae- especially as it has been getting worse. We generally do 10% changes at a time. We have also tried the snails. The problem is that there is soooo much algae, they eat till they are full and haven't moved more than about 4 cm in a day... and then there is that worm- polychaete Oenone fulgida which we only discovered recently after we bought a clam and 2nd morning found it completely empty, covered in slime. We have bought numerous snails but they had always dissapeared myseriously- go behind the rocks and never return. So, even when we DO buy snails, they don't do much or get eaten by either the worm or the bloody mantis. (We originally had 2 mantis, but we caught one of them in January... the other one is much smarter and remains elusive) I'm not sure I want a sea hare, they get pretty huge, and I imagine they can disrupt the stone placement pretty easily. Good for a short term solution, but when the algae is all gone, then there is a huge slug...

[hOOPSNAKE]

Hi cdm2012,
We started out cleaning the scrubber religiously when we first got it- eager to see a reduction so we did do it every 14 days. Then, after not seeing much growth we stretched it out to 21 days. When we didn't see much difference in the extra time, that's when we began to scratch oour heads and wonder what is going on, so we experimented, and left it for 2 months- and you see the result.. still not a lot. That's when we decided to come here. and as SantaMonica just posted, the air hoses look like that, algae on the outside.

What might have been contributing to the algae is it has just been summer and it has gotten direct light just before dusk for about 10-20 mins which hasn't helped- it's not strong light, but it is more that it should be getting. Hoping now it is Autumn and the sun's trajectory has changed again, that we will get time to get on top of this before next summer :)

[hOOPSNAKE]

Hi SanatMonica!
We have a second HOG we purchased at the same time as the first, we will put that in and see if we can make a dent. Someone mentioned that the 2 led's in the version of HOG we have might be too much and that is what is causeing the spot that never grows? We are thinking of 'jumping' one of the lights, but having 2 units working as you suggested. Does that seem like a plan?

[MorganAtlanta]

I'd throw in a rabbit fish or two for a while also. Fish are easy to trade off if you do end up conquering the algae.

[SantaMonica]

Just reduce hours until the spot goes away.

[kotlec]

Display lights are much stronger that HOG ones. So your display scrubber possibly is much stronger.
Just theory.
If you will reduce display lights for few days and look for increased growth in hog, that would not hurt much. On the positive side theory will be proved or not. :)

[Floyd R Turbo]

Srusso had a working theory he called the "rule of PAR" which said that your PAR of your scrubber needed to match or exceed that of your tank. Good in concept, but 660nm reds are not measurable by that method so that throws a wrench in it. But what Koltec says is probably true, with display tank lights burning all day in the 100s of watts (equivalent, at least, for radions) and 2 660s on the HOG, it's not even a competition.

[SantaMonica]

Not PAR, but overall scrubbing power, which is a function of size, attachment, lighting, and flow.

A display has weaker lighting and flow, but has the advantage of size.

[Floyd R Turbo]

That's probably a more accurate way of thinking about it.

[Rumpy Pumpy]

Hi Rumpy, the algae scrubber light is on overnight, so I don't know that there wouldn't be enough nutrients in the water, and obviously, from the level of algae there is a heap to go around. What we didn't mention in our opening post, and should have to give you the fuller picture is that we do do water changes and manual removal of existing algae- especially as it has been getting worse. We generally do 10% changes at a time. We have also tried the snails. The problem is that there is soooo much algae, they eat till they are full and haven't moved more than about 4 cm in a day... and then there is that worm- polychaete Oenone fulgida which we only discovered recently after we bought a clam and 2nd morning found it completely empty, covered in slime. We have bought numerous snails but they had always dissapeared myseriously- go behind the rocks and never return. So, even when we DO buy snails, they don't do much or get eaten by either the worm or the bloody mantis. (We originally had 2 mantis, but we caught one of them in January... the other one is much smarter and remains elusive) I'm not sure I want a sea hare, they get pretty huge, and I imagine they can disrupt the stone placement pretty easily. Good for a short term solution, but when the algae is all gone, then there is a huge slug...



Have you considered breaking down the tank completely? Then you could get rid of the worm and the mantis and perhaps replace some or all of the rock?

The existing rock you might be able to recycle by placing it in a separate unlit container and using another scrubber and/or GHA and/or skimmer to "purge" it.

[Floyd R Turbo]

... and then there is that worm- polychaete Oenone fulgida which we only discovered recently after we bought a clam and 2nd morning found it completely empty, covered in slime.

Hey I just learned something! Glad I haven't come across one of these guys myself.

About 3/4 of the way through this article:

http://www.reefkeeping.com/issues/2003-04/rs/

Says find out which rock he's in, and flush him out with carbonated water. Interesting.

Sounds like he is your biggest problem, eating all your snails is adding to the bioload of the tank. I don't think there is a cube-equivalent for live snails.

[kotlec]

I don't think there is a cube-equivalent for live snails.

:D :D :D

[hOOPSNAKE]

yeah, we have been pretty unlucky with our hitch-hikers- never again will we go all live rock, it's just too depressing. Thinking about tearing the tank down and get them out once and for all- big job...big big job.