ac500 "fuge" - why?

Ok I've read up a lot on these and it seems that the people who use them as a fuge on 10 gallon or smaller aquariums is about equal to the people who use them as a fuge on larger "nanos" like 20-30g aquariums.

I recently had quite a nightmare trying to set up my ac500 as a fuge and am wondering if I need to do more reading or if I did something wrong? So far it's been a costly failed experiment.

This is all because I wanted to move my Mantis Shrimp from her 2.5g home to her permanent home of a 5.5g. Since she will potentially harass the cleanup crew, I was looking at other ways to reduce algae and sediment. I thought having some caulerpa in an ac500 sounded like one way to keep nutrients down. So I bought the ac500 (retail no less, what a ripoff). After reviewing exactly how every set theirs up (and noting the tank sizes, I saw many eclipse 6g minibows etc), I cut a bit of plastic and put it in as the divider to keep sand out of the pump. Then I filled it and turned it on.

1. What kind of crack monkey would use this on a 5.5g tank? It (literally) created a hurricane vortex of swirling sand. My water was fouled for a week. I moved it to a 10g filled w/ simple tap water just to test the current in there, but it was still way too strong, by like 50 long shots.

2. How can you reduce the flow? I even tried various methods to restricting the intake, but it was just not good enough

3. Have you had any issues with quality? This whole thing is a POS. The pump is noisy. The unit has plastic rattle/vibration. The first two I got were busted in the same location - and they came from different places, so that break is probably due to improper packaging rather than handling/shipping. They were busted on the right front corner, where the plastic lip/spillway is. The box has no padding there ...

4. Anyone tried something smaller like an ac300? Regardless of my gripes with quality, I still want to find a way to hook up a fuge to this tank, and an ac300 still looks like the best design. Comments on the usefulness of an ac300 on a 5.5g? I would like low to moderate current.

If you think the 300 has enough room for what you want to put in go for it and buy an extra impeller for the AC Mini. I had a 500 on a 10 gallon and thought it was way too much. I now have the 300 on a 5.5 and it's just right...I do wish I had more space, but it works. Just pop in the mini impeller and no more mods are needed. I ran the 300 for a few weeks with no mods, just the surface skimmer attachment. It rattled, hummed and swirled...now with the mini impeller it's quiet, calm and just the right flow for a fuge.

Thanks ODOG, that's exactly the information I wish I would have seen before I blew my load on the ac500.

Right now I just threw on 2 of my old whisper HOB's - one w/ polyfilter/chemipure and one with rubble rock.

You could also modify the ac500 impeller. Just cut some of the blades off and it would create low flow.

my 2 cents....

Good idea, heuerfan. Would it be best to shave the existing blades down or to cut every other one off?

I just purchased one to put on my 10 gal. I did so after doing some research here using the search function. Most people who have used this unit on a 10 gal have the skimmer attachment and set the flow to its lowest level. The combination of these reduces the flow to where it is fine for a 10 gal. Using this on a 5.5 might be a little much. Did you search before buying? The last thread I read on this before I bought it specifically mentioned this being too big for their 5.5. I'm not slamming you, just wondering how much research you did.

Gerde, just wondering if you were using the 500 as a fuge or filter. I ask becasue I doubt that what you mentioned would have helped Huarang. I still think that the flow is too much for a fuge unless you add a baffle of some sort.

Hwarang/Heuer, do you think that by cutting off some of the impeller it could get unbalanced and not work well or make alot of noise?

I did a bunch of reading that included threads and pictures here, on RDO and reefcentral (nanos forum). Reefcentral seems to have the highest % of proponents of the ac500 on sub10g tanks...

When I purchased it, it did not have the surface skimmer option (the store didn't have any).

Anyhow, I'm looking at getting the ac300 w/ the smaller impeller and surface attachment. That oughtta do it just right.

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ODOG - yes I think it *would* be unbalanced. Even if it worked or seemed to work well right away, I bet the imbalance would wear out the impeller knob or the socket it fits in after not too long.

It would work, thats what i did to my aq200, there are 4 blades, i cut 2 off. Its been running for a year no problems. You can trim one of the blades, or cut it off. Take your time and see what works best. Or just purchase a miniaq impeller. Don't see why cutting the prop blade would make the entire impeller unbalanced.

I've also done this to my powerheads as well.

my 2 cents!

hey did you fit the mini impeller in the ac500? i read earlier today that it won't fit- that's half the reason i want to downgrade to the 300 - to get the "bonafide" (not jimmy rigged) impeller, one that's lower output ... but if i can do that on the 500, i'd rather keep the volume of the 500

Im just going to sit back and keep my eye on this thread.

I plan on getting a AC500 on my 10 gallon once I get it setup. I dont really have anything to add since I dont have experiance with the filter yet........Soooo Im just going to bounce.

I don't really see the point of it. First of all, if you're using it for macro export, the limited amount of macro grown in there isn't going to do much in the way of sucking up much out of the water column. Also, by the time most macros take up and utilize those nutrients, they've already broken down into a state this is not great for your tank.

If you're using it as a refuge, the pod life that is making it to the tank is extremely MINIMAL...we're talking miniscule. Is it really worth the effort?

Hey skylsdale, enough negativity out of you...just kidding. LOL. Yeah it should work. I am currently trying to modify mine now. In addition to cutting impellers, I have read about using the skimmer, removing the black plastic piece around the impeller, and also drilling a small hole in the pipe to decrease flow. My 500 came with two pipes so I might try and do this. Also, the loud noise you hear may actually be sand and gravel that you kicked into your impeller when it went full blast in your tank. I would mod it and try it in an empty aquarium or something. May be worth trying it in a 5 gallon bucket first. Also, someone else mentioned hooking a > 200 gph powerhead or pump to the piping and dont plug in the filter. I was told it should work just as well. I wouldnt give up since you have already bought it. I know when my fish were in QT for ich I had a pod explosion in my tank. I would expect the HOB rfugium to do the same. Good luck!

It's not negativity at all...just a simple matter of logistics and practicality.

MillerLite, good call on the sand and impeller. That's *some* of what it was. The pump is noisy anyhow, and the lid rattles. I emptied the filter out and cleaned the impeller boot with a q-tip and then flushed with water .... 5 times! I was being very um ... "detail oriented" about sand in the impeller, and after I got it out, the thing was still noisy.

skylsdale ... thanks for the input. I have a couple of questions for you...

1. What about the benefits of the rubble rock in there instead of macro?. Might that be a nice filtering boost? What if it was some rocks and then macro on top?

2. I dunno about you but my caulerpa grows like a grassfire drinking gasoline. I think it's worth a shot. Has anyone every done any actual experiments where they had a nano, kept it stable then added a fuge to see the benefit? A lot of ppl keep macros in fuges on their nanos ... are they all fools?

3. You mentioned organics etc breaking down. Got a link to something semi-technical about that, and how it works?

I'm using the 500 as a fuge and macro growing area, not as a filter. I really didn't want to spent $100 for a CPR aquafuge. $30 for a 500 with the skimmer attachment seemed like the right price to me, and the largest water volume for the money. It is also large enough for me to put the heater in there and get it out of the tank.

1. What about the benefits of the rubble rock in there instead of macro?. Might that be a nice filtering boost? What if it was some rocks and then macro on top?

Rubble rock might be better. If anything, I would cram it full of LR and then just use that as an extra area for filtration via the rock.

If you stop to think about it, you're going to still have a relatively small population of pods, etc. in that AC500. Even if you throttle down the flow, it's still may not be the most ideal environment for them to thrive (constant flow through the particles of rock may impede and/pr prevent detritus from settling, which in turn limits the diet of the pods, which prevents them from really being able to breed on a larger level). Even if they do begin to breed, how many of them do you think are actually going to get physically close enough to the lip of that AC500 to actually get swept over the edge? I would guess it's an obscenely smaller number than most people imagine. Also, assuming that we want to get things like detritus out of our tanks as soon as possible to prevent breaking down of waste and buildup of phosphates (which is one of the major things that detritus releases), do we really want it settling in the AC500 for things to eat? Is it worth it? So, you have detritus decomposing and breaking down, releasing nutrients and phosphates into the water...and then down the line somewhere some caluerpa manages to absorb some of it...but not all. IMO, it would just be better to try and deal with the root of the problem: get the detritus out before it breaks down via plenty of flow to keep it suspended and remove it from the system regularly via skimmer/siphoning.

2. I dunno about you but my caulerpa grows like a grassfire drinking gasoline.

I'm not disputing it's growth and uptake of nutrients at all. However, I want to get nutrients and compounds out of the water before it comes a problem. Ideally, this would come from getting detritus out as soon as possible. By the time macros are able to take in those nutrients, they have already broken down into a form that is bad for the tank. So, it's kind of a catch-22.

Has anyone every done any actual experiments where they had a nano, kept it stable then added a fuge to see the benefit?

I think it's more along the lines of seeing nitrates, etc. go down once they get an established refugium. But again, there are more nutrients and such that we can't even test for murking up the water column. However, most people go about it with an "out of sight, out of mind" mentality.

A lot of ppl keep macros in fuges on their nanos ... are they all fools?

I wouldn't necessarily say that, but maybe they just haven't really looked at it more in-depth. Or just assumed the common dogma and methodology was absolute truth. It works...but not really in the way and as well as most people are led to believe. The process, IMO, has been oversimplified a bit and led people astray in their understanding, thinking that their methods are much more effective than they are.

3. You mentioned organics etc breaking down. Got a link to something semi-technical about that, and how it works?

Here is a comment made by Eric Borneman about it:

"refugium has changed...the deifinition and we've talked about before....we actually keep a refuge, not a refugium and the idea was to provide areas for growthof critters otherwise preyed upon. Now, however, people equate them to filtration areas, which is kind of silly since the rock and coralss and main tank are probably doing far more than a small box with some macroalgae in it. Still, even that provides a function. If these areas were much larger, they would be far more functional."

I think this brings up a very good point in the ratio and proportions of the containers we use for refugiums and filtration. Again, I don't think a filter body is really going to make a worthwhile dent in the system's overall health.

Also, check this link (the very last post at the bottom made by Bomber): http://reefcentral.com/forums/showthread.p...s&pagenumber=29 Try doing a Google search using 'phosphates' 'bacteria' 'marine' 'sediments' and things like that. Also try organo and polyphosphates. You should get plenty of information.

Well here are my findings. These were from 3 different tanks, a 30gl, a 20g &a 10g.

We setup the 20g and the 10g about the same time. we did not set them up with fuges. simply with just heater, light, ph's and lots of rock and sand. We had some pod growth, and the tanks stabalized quickly. we kept params to zero except for nitrates always hovered around 10ppm.

We decided to setup fuges for pod production and to see if we could lower the nitrate levels. We put a AC500 on the 20g and an AC300 on the 10g. We used the surface skimmer attachment with the bottom vent closed, and a smaller impeller on the ac300. We also turned the flow down all the way. We filled both with a few chunks of lr from the tank along with some sand. Then we added some macro and a little booklight to each. After one week's time we had a HUGE pod explosion that never quit. my clown and bi-color couldn't eat enough of them. And our nitrates dropped between 0-5 ppm and stayed there. We had a few snails lay eggs and hatch, and we would occasionally harvest the macro that grew like crazy.

I think it works. For pod production, nutrient export, and to act as a refugium for baby snails. The idea that it won't export enough nutrients makes me question the size ratios that many people are running on their tanks. My lfs dropped their nitrates down to zero by adding a fuge that holds a gallon of water to a 400 gallon tank. The ac500 brought my nitrates down to zero by adding its small volume, but a much greater volume to volume ratio than the lfs. the AC300 on the 10 has an even higher ratio than the ac500 on the 20g.

I think it does what it is supposed to. And with the right modifications you can get the flow to where it just drips out into the tank. I run a heavy load on my tanks, and i don't want to run skimmers. The refugiums definitely work for my tanks and keeps things clean while adding live food for my critters and corals.

sorry. double post from a bad connection.

Hmmm interesting

*absorbs*

Thx skylsdale and NanoAmyDee. Stuff to think about!

I think it works. For pod production, nutrient export, and to act as a refugium for baby snails. The idea that it won't export enough nutrients makes me question the size ratios that many people are running on their tanks. My lfs dropped their nitrates down to zero by adding a fuge that holds a gallon of water to a 400 gallon tank. The ac500 brought my nitrates down to zero by adding its small volume, but a much greater volume to volume ratio than the lfs. the AC300 on the 10 has an even higher ratio than the ac500 on the 20g.

Again, you're only looking at nitrates. How did the macros affect the other levels of organics in your tank (such as phosphates)? Low to zero nitrates doesn't mean your water is clean...but I would venture to say that most people don't concern themselves with much of anything outside nitrates, but ironically, it's those organics that often lead to most of the problems people run into with their tanks. Check the link I gave and you will see why.

that thread is huge (and i don't see the link you mentioned inside the thread) ... i'll have to read it some time when i'm not at work ...

The link I provided a couple posts back should put you right to pg. 29 of that thread. If not, just click to pg. 29 and read the post at the very bottom by Bomber.

Yeah, it put me there but the only links by bomber are the URL in his sig ... *shrug*

I'll check for it again later. I gotta go stick my head in a buncha actionscript and php.