Advice on Freshwater refugium/sump


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Okay so I saw a post somewhere on the web today that a gentleman said to put a canister in a sump and use it as a return. Because he said biological filtering like bio-balls and such is overrated. That live sand, rock and plants take care of the waste better by not just turning nitrites into nitrates but also taking care of the nitrates. He said this means less maintenance. So he said a design something like the pictures if you can make out my terrible drawing I did on my note 9. But this will maximize refugium area while housing mech, bio, and chemical filtration in the canister which doubles as a return pump. Dont quote me on every detail the guy said but I want to say he said you won't need a really strong flow from the return pump as you want the water to slowly go through the fuge so the good bacteria, snails if you want, or whatever you decide to do in the fuge can take care of the nitrites, nitrates, and ammonia. I'm trying to find a good not so simple sump/refugium build I'm doing myself in a 29 gallon Petco special aquarium. This will be for my 72 gallon bow front heavily overstocked with 22 all male Peacock Cichlids, 2 Synodontis Angelicas X Eupterus Catfish(I think they are aka upside down catfish?), and 1 Blue Eyed Lemon Bristlenose Pleco. As of right now I have 3 canisters on it and 2 big sponge filters. One SunSun 504b, a Penn-Plax Cascade500(I think), and a EheI'm 2217 Classic(ole faithful). I'm not to sure about the sump plans this guy had but wanted some opinions. I also don't think some of his information was correct. Anyway, shoot me some ideas. I don't want it simple. I like to make things!



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More than 10 years
While some of his things thag he saying makes sense, a lot of it.. eh, highly questionable. Do you have a link to his post so we (I) can see? Its a lot easier to understand without the second habd information.

While plants, rocks and sand does allow colonies of bacteria to develop, they are unlikely to have much surface area or water flowing through it to adequately filter your water. Unless you force the water throuth the rocks/substrate, its not really going to filter much out.

A better way (using your idea) is to add a glass baffle between the socks and the refuge, and fill it up with porous media (lava rock, ceramic media, gravel, sponges ect) so you force the water through some of it (filtering ammonia and nitrites) before hitting the fuge. Then fill out the fuge with fast growing stem and floating plants to further reduce ammonia and nitrates.
Of course, there's helps of better sump designs out there... so I'd suggest looking into them for some inspiration.

A canister filter is also unlikely to do well submerged, and for best performance, manufacturers reccomend installing the canister underneath the aquarium (or in your case sump). You'll probably find it better to run that separately to the sump system, and then use a small pump to circulate the sump, or a larger pump but with a T-junction flowing back to the start of the sump, and using a ball valve to control the flow.


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5 to 10 years
I don't think the canister filter in the sump makes any sense at all from an economical perspective. You can buy a submersible DC pump for less than half what you'd pay for a canister that would move the kind of volume you'd want.

The whole idea of filter socks in the sump also don't make much sense to me. They'll work, but they have to be a maintenance nightmare. If I'm building a sump it's because I want massive filtration and less work, not because I want to be cleaning filter socks every week. I'd skip the initial baffle and just put a couple 3" pieces of filter foam vertically across the width of the sump. Massive matten filter that you likely won't have to mess with for more than a year.

I do agree with his disparagement of bio-balls. They're intended for moving beds. If you don't have a moving bed, you don't want bio-balls in your filter.

I'd suggest taking a look at YouTube videos from Jay's Aquarium (no relation) and also Dr. Kevin Novak. Jay doesn't talk directly about sumps that I recall, but it shouldn't take too much imagination to apply some of the things he talks about to the sump. Dr. Novak talks about methods of reducing nitrates through filtration. His biocenosis basket is something you can build cheaply and add to the sump without taking up too much space, so you can try it and if it doesn't work for you, no great loss.

One of the things with a more open sump like you're talking about is that the water is flowing through the entire height and width of the sump, so even if you have a fairly high flow back to the tank you won't really have that much current in the sump. Certainly the dwell time of the water in the filter media will be much greater than in a canister with equal throughput because you have so much more media.

I would suggest against lava rock. It has a lot of crevices on the surface, but they don't lead into and through the rock. You want something the water can work all the way through.

Frankly, I'd just do two or three 3" piece of foam in decreasing porosity (10PPI, 20PPI, then 30PPI) for mechanical and nitrification, then use the rest of the sump to deal with the nitrates using something like Biohome, the Novak biocenosis baskets, hydroponic clay balls, fast growing plants that get nutrients from the water, etc.

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