DIY refugium aka veggie filter

Ali · Post by **Ali** » Wed Jun 22, 2005 10:03 am

Hey guys I read that a lot of you have veggie filters on your tanks and tey help maintain a low nitrate level. Well can someone draw up plans for a HOB type for everyone to see? I have to use hob bcause the tank in question dosen't have a sump. Thanks

Bred · Post by **Bred** » Wed Jun 22, 2005 10:10 am

Not DIY, but CPR makes a constant-level HOB overflow box that allows you to install a sump w/o drilling holes in the tank. CPR Overflow Box.

Veggie filters need to be lighted and allow space for plant grow-out, which would be a trick in a HOB refugium. I don't see it working out.

RTR is the king of veggie filters.

He might have some ideas.

I meant to ask - what size is the main display tank? Is high light / heavy planting not feasible within the display?

Ali · Post by **Ali** » Wed Jun 22, 2005 10:30 am

I have two tanks I want to use this type of filtration on. One is a 240g and the other is a 60g. They both are placed very close to windows and so get a lot of sun. I already have a hob sump but it is only like 16"x 6"x 4". I plan to fill it up with watersprite. Will it take care of the 60g's needs and reduce the nitrate level down to 0?

Thanks

Bred · Post by **Bred** » Wed Jun 22, 2005 10:42 am

It would help lower nitrites, yes... But it would not eliminate the need for routine partial water changes. Here's the gist of it:

RTR wrote:And do please remember that we are using nitrate as an indicator of pollution build-up in the tank. Nitrate alone, and nitrate per se is not the real issue. The issue is nitrate plus minerals/TDS plus organics/DOC including hormones, phenols, etc., plus colorants - all the undesirables that accumulate in tank water. It is used because it is easily and fairly clearly testable, especially on a comparative basis: "I start with water at 10 ppm. After 10 days it is 20 ppm. If I do 50% partials every week I will not have water problems." That is the supposed reasoning, and it works in simple FO setups in FW.

If you are talking marine tanks with a skimmer and live rock or with a 24/7 lighted refugium, it does not work that way. if you are talking FW planted, it does not work that way. If you are talking BW with a plenum, it does not work that way. None of those cases have conventional cycles for nitrate or for the other and equally important pollutants. The relationship of nitrate titer buildup in simple setups is too important to trvialize it. But you cannot fall into the trap of thinking that nitrate is the whole ballgame - it is an important component, but just one item on a huge list of items which can build up in tanks.

Full thread here.

Ali · Post by **Ali** » Wed Jun 22, 2005 11:28 am

Currently I do water changes every other day.

I just found out that I have that model that you were explaining made by CPR. How do I get this started? I'm thinking of connecting the intake to a pump inside the aquarium and so the water will go through all the plants and back into the aquarium by overflow.

Bred · Post by **Bred** » Wed Jun 22, 2005 11:41 am

That's exactly right. Just set a return pump (with prefilter) in the sump and fill 'er up. Away you go!

If your return line (the one pumping water back into the main tank) is submerged under the water line of the main tank, you will need to guard against back-siphoning in case the power fails. You can either install a check valve in the line, or you can drill a hole just below the water level in the return line--the siphon will be broken as soon as the water drops below this hole. This will keep too much water from emptying into the sump and going all over the floor.

Bred · Post by **Bred** » Wed Jun 22, 2005 11:45 am

oh and obviously you want to make sure the overflow box has a GPH rating high enough to handle the return flow... which model do you have?

Ali · Post by **Ali** » Wed Jun 22, 2005 1:33 pm

The model is CYHO

Also the return line is just a waterfall. Is this all right?

This seems kind of risky to connect the pump to the intake without a ball valve or something because how do I control the flow if the pump is to strong.

Bred · Post by **Bred** » Wed Jun 22, 2005 1:42 pm

CYHO? I don't know what that is. Are you sure it's the same as what I posted? can you measure the width of the unit for me?

What kind of pump are you using for the return?

Post by **RTR** » Wed Jun 22, 2005 1:42 pm

I have no experience with FW refugia in the HOB format. I'm more used to a sump format, where space is not limiting. I am currently running some trials on FW 24/7 lighting (more akin to the SW HOB macroalgae refugia) but still using tanks. It is too early in the testing for any conclusions on constant light or the plants useful for that.

Post by **Myaj** » Wed Jun 22, 2005 1:57 pm

Bred, from what i understand, the unit he's talking about pumps water in, like an Aqua Clear power filter almost, then just lets it waterfall back into the tank. There is no return pump.

I've never understood that about sumps though either, how do you balance out the two pumps so one doesn't get a head of the other and overfill the sump? I guess I just never really looked at a setup that close. I can see how it would work with a predrilled overflow system, but that's it...

Bred · Post by **Bred** » Wed Jun 22, 2005 2:02 pm

You need a pump to lift water from the sump to the main tank. That's about 4' of head in most setups, not counting right angles in the return line. You can't do it with anything else.

You only use one pump in a sump set up. It moves the water from the sump up into the main tank. Water trickles out from the main tank via the overflow box at the exact same rate, provided the overflow has a higher flow capacity than actual flow from the pump. (If not, you're in trouble.)

It's quite a beautiful system, really.

//edit... you could use multiple pumps for redundancy, but they'd all be doing the same thing: pumping water up from the sump into the main tank. you let gravity do the work in bringin the water back down. it's practically impossible to move water between tanks using pumps alone -- just imagine trying to get the flow rates the same! i [heart] gravity.

Post by **Myaj** » Wed Jun 22, 2005 2:13 pm

Okay.. so the only way a sump works is with an overflow box. Gotcha. So if you don't have a predrilled tank with overflow, can you do it?

I'm pretty sure he's just talking about a hang on back refrigum, not an actual sump. Kinda like this:

http://www.drsfostersmith.com/product/p ... 004+113080

Only one that waterfalls back in instead of being piped in.

Post by **Myaj** » Wed Jun 22, 2005 2:14 pm

Here's a good link to DIY stuff, I'm sure they have some sump/hang on back stuff:

http://ozreef.org/content/section/2/29/

Bred · Post by **Bred** » Wed Jun 22, 2005 2:46 pm

Myaj wrote:Okay.. so the only way a sump works is with an overflow box. Gotcha. So if you don't have a predrilled tank with overflow, can you do it?

Yep, an overflow box is a must. For undrilled tanks, see my link above to CPR overflow boxes. They work using an W-style siphon, instead of a U-siphon to prevent siphon breaks.

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DIY refugium aka veggie filter

DIY refugium aka veggie filter