Refugium/Sump

[::pete::]

I am building this (http://jjgeisler.com/reeftank/55g_sump-refugium2.htm) for my tank and have a couple questions.

Is the eggcrate and space necessary at the bottom or could it just be a sand bed w/LR?

I am going to use a submersible pump for the return because I have one ... OK?

As for skimming I want to get rid of (hide) the equiptment on the main tank and would like suggestions. I currently use a seaclone, but it will splash creating noise. Do I use it w/ modifications or is there a hang on I could use?

The main purpose for the refugium/sump for me is Nitrate removal and hiding equiptment. I will not be using a 55gal, but instead a 30gal (because it fits under the 100gal tank in the stand) should I add a pump to the main area for circulation?

I would like to have it up and going by tomorrow as I am expecting delivery from IPSF. Thanks !!!

Should have put it in DIY :roll:

[matt]

Pete;

I gave it a quick look; I'm probably forgetting a few things, but here's what I notice right away.

1. Eggrate for "plenum" underneath sand bed is not needed; most people would say detrimental.

2. The eggcrate/baffle arrangement where the water drains from the tank is good, but consider putting the eggcrate higher up, maybe about halfway up the tank wall. That way the water flows through the eggcrate, and if you ever use some sponge or something for mechanical filtration, the flow will help keep it in place. (believe me, you'll aprreciate having that option when scrapng agae or anything that creates a mess in the tank)

3. Don't use bio balls on this eggcrate; live rock rubble works great for bubble dispersion and it won't contribute to a nitrate problem.

4. If you're using a submersible pump, make a little area for it with dividers so the sand can't get in it, BUT, make sure those dividers are fairly low. IMO, the way this one in the drawing is designed has a major flaw; the evaporation area is very small and you could run the pump dry easily. If you're drilling for an external, just use a little baffle to help keep sand out. Run your water level higher than these baffles so that the evaporation is from a larger part of the sump.

5. You don't need any powerheads; you're running your return pump volume through a smaller area; there's plenty of flow.

6. If you're making baffles/dividers that will withstand water pressure, consider using glass dividers if it's a glass tank. Silicone really sucks adhering to acrylic; people use it on overflows all the time, but that's because the water pressure on a corner overflow helps to hod the whole thing in place. If it's a glass tank, the best thing is glass dividers attached with silicone. Another option is to use weldon #40 to attach acrylic to glass; some guy did an experiment on that and it worked well.

HTH
Matt

[GaryP]

Joshua,

I wouldn't think Weldon would work at all on glass to glass. Weldon and other acrylic compounds aren't really an adhesive at all. Its more like a solvent. It melts the acrylic and causes it to chemically weld after the solvent dries. Sort of like partially melting two ice cubes then sticking them back together again in a freezer. The crystalline structures join together.

Gary

[matt]

Weldon #40 is not a solvent. It's a polymerizing cement, a syrupy two part mix. On the IPS chart(manufacturer of weldon) glass is not listed as one of the materials it bonds to. But, some guy on one of the boards did a little test with several adhesives bonding acrylic to glass, and weldon #40 apparently was much stronger in tensile strength than silicone. If it were me, I would use glass dividers attached to glass with silicone, or possibly glass "guide strips" attached to the aquarium wall with silicone, then slide the acrylic baffle in place.

[::pete::]

In the LFS (http://www.hi-tide.net/P-location.jsp) I went to the owner showed me two set ups. 1 was @ 4' and the other was @ 6' both were around 10 yrs old. The 6' one was seperating a little at the top, but due to stress (bowing) on the glass of the tank. Aquarium silicone was used in both. I dont know about weldon, but 10 yrs with silicone and glass to acrylic I would say is pretty good. He sold me the tank and acrylic for 30. dollars and the tank is only 29" I dont think there will be a problem and apreciate the help.

Matt as for making the inlet shorter (eggcrate) would you still leave the "channel" long and just put the eggcrate in the middle or shorten the entire deal? Thanks

Ill post some pics after its set up, just waiting on Saturday cause I get my ROSE BTA !!!! :D

[Jenn]

I just wanted to say thanks for this topic - I just received a 55g aquarium that I was thinking about doing something like this with. The problem was, I had no idea how it all works or even where to start.
Thanks Prafferty - great illustration and directions. :)

[::pete::]

Your welcome Jen, however they are not mine I found them on the web a while back and I am just now getting around to it!

[matt]

My guess is that glass to glass with silicone would be quite a bit more reliable than acrylic to glass with any adhesive. Pete, you can try roughing up the acrylic with sandpaper in the area where you want the acrylic to grab. As far as the channel for the water goes, I'd still leave that long and just raise the eggcrate. That way the water would flow down through the eggcrate almost to the bottom of the sump, then back up over the divider. You'll get some bubble dispersion that way. Have fun!

[::pete::]

The aquarium silicone seems to be holding and with the water pressure I hope it keeps holding. Here it is ... downsized.

[Instar]

I would be interested in knowing what chemicals weldon leaches into the tank water after its cured. Anone know?

[Instar]

If you use a large particulate substrate like 1/4 inch crushed aragonite, use the eggcrate and make it a plenum. In that case you will need a powerhead in place on a lift tube for 8 months to seed the plenum. If you use sand, skip the eggcrate like matt said.

[GaryP]

Larry,

I'm missing something here. Maybe you can set me on the correct path.

It would seem to me that there is greater permeability in coarse substrate than fine. Therefore there is greater vertical migration of water through the low oxygen gradient at the bottom of the DSB. It makes sense that you would need a deeper coarse than fine sand bed to establish the gradient for denitirification to take place. Isn't the purpose of a plenum to increase that circulation. So I guess the question is why would you use a plenum with coarse instead of fine substrate. That seems to be the opposite of where my logic leads me, unless the plenum itself is the anaerobic zone and the coarse sand is only serving as an oxygen stripper to get to a low enough Redox potential for denitrifying bugs.

Please let me know where I am going astray in my logic here.

Thnx,
Gary

[Henry]

Gary here is a link that discusses plenums

http://advancedaquarist.com/issues/sept2002/feature.htm

[Tim Marvin]

Plenums are a filter of the past. People are finding they crash on them and wipe out the entire tank. If you use too fine a sand they clog up and that is what causes the instant death to your tank. I wouldn't recommend a plenum unless your are an expert reef keeper and have a place to move all the livestock when it crashes because you can't fix a plenum with everything in the tank. If you build one outside of the main tank you'd better have a good eye and move fast when it starts crashing. From what I understand Scott Morell from GARF is no longer useing a plenum due to a crash, and I am not sure if GARF is useing them either.

[matt]

Cool article; I have a feeling that one reason plenums get kind of a bad rap is because they seem to be pretty specific and complex to set up correctly.

[Tim Marvin]

That is what I understand. They need to be totally dark or they will produce O2 from algae down deep. They also need the correct sand sizes. Too complicated for me to try so I can't give first hand advice. I feel that you should either have an experts eye or do lots of water testing every couple days to monitor these filters. We are haveing such great results with refugiums and "Matt's monster skimmers", why grasp at other filters, especially since they do the same thing and are easily monitored. I say go with what works.

[GaryP]

Tim,

At some point I read a bunch of info that really hyped plenums. I also met an LFS owner that installed him in all of his tanks. I was thinking about putting one in my next tank. Then I started see some of the negative stuff and just went to a DSB. I had run either bare bottom or shallow coarse sand beds before that (not knowing any better). Still, I thought I had some understanding of how they worked. I can see the problem with fine sand and a plenum now that I think about it. It would be difficult to find one with a fine enough mesh to keep my sugar sand from infiltrating into the plenum.

BTW, the LFS in Pineville, NC that Pete gave the link to above is one of the finest shops I have ever done business with. Its primary business directed at reefkeepers. Its fairly small and new but the owner (Tommy) is one of the most knowledgeable I have ever met. When you asked him a question, you didn't get an answer, you got a lesson. The are the driving force behind the local frag club and host the meetings as well as arranging joint meeting with other frag clubs in surrounding areas. They had a great frag tank that had frags for anywhere from $5-20. They were also raising their own frags. I was doing about $100/mo. in trades with them when I lived there. I only wish Tommy would franchise a shop here. :)

Gary

[Tim Marvin]

Do you stay in contact with him? I'd be interested in how those plenums are doing. Sounds like a great guy, we need more lesson givers than just sales people. A lot less trauma to livestock if people had a short lesson before a purchase.

[GaryP]

Tim,

No, unfortunately I haven't stayed in touch. I moved from there last April. I just thought it would be good to plug a well deserved LFS for a change, even if its 1400 miles away. I dropped Pete a PM and asked him to say hello for us. There was a definite "family atmosphere" at Hi-Tides. Its nice to go to a shop where you felt more like family than a "sucker."

The staff at the only other SW LFS in the Charlotte area were paid on commission. Need I say more?

Gary