Refugium and undergravel filter

[BurgerFish]

Hello,

It's hard to clean the fuge buttom from detrius. Maybe I can install an undergravel filter with reverse flow? Somebody did that?

Thanks

 

[dmsc2fs]

do you have gravel in your fuge? I would think a reverse under gravel would drive the detrius into the gravel and not into suspension. if so you didn't gain anything, you still need to vacuum it if that is the goal? If you have no gravel a powerhead would be a better option to stir the bottom I think.

 

[BurgerFish]

No, no gravel. Bare glass.

I tried powerhead, it doesn't work cause of chaeto.

 

[minus9]

The only natural way of processing detritus is employing a deep sand bed, which would make it an actual refugium. The other options are filter socks (or similar, floss) or manual removal with a vac.

 

[Jekyl]

I use an RUGF system in my 90g. Can you even get the plates needed to fit in your sump? Never heard of them being used this way.

 

[Jekyl]

Would need to find a plate that would fit the area of the sump, add 3" of crushed coral or dolomite, then find a pump that can push water into the plate at around 100gph or so.

 

[BurgerFish]

My refugium is 12x12 inches. One plate of Penn-plax filter must fit.

Deep sand bed require more maintenance.

 

[minus9]

My refugium is 12x12 inches. One plate of Penn-plax filter must fit.

Deep sand bed require more maintenance.

A properly set up DSB requires no maintenance, which is the key. Good flow over the bed and the right critters to do all the work for you.

 

[GARRIGA]

Undergravel filter with airstone and 4" pumice plus a top layer of 2" of coral skeletons such as Reborn will not just assist in nitrification of that detritus but will also perform denitrification along with melting those coral skeletons identical to a calcium reactor due to acidification via nitrification. Denitrification will release alkalinity lost during nitrification. Powerhead is going to clog it and that will require maintenance. This will also allow decomposers to break the detritus into elements that the chaeto can utilize. Decomposers being heterotrophic bacteria along with amphipods and copepods that likely already exist in the chaeto. Consider adding nassarius snails to sift the gravel and consume that detritus. Conch might help as well.

Replace the coral skeletons as they melt. Just layer on top since the top layer will be exposed to the highest level of oxygen and conduct the bulk of that nitrification. Let nature do the work. It has for billions of years before we started boxing fish with water.

 

[Dan_P]

Hello,

It's hard to clean the fuge buttom from detrius. Maybe I can install an undergravel filter with reverse flow? Somebody did that?

Thanks

In what way is it difficult to clean the refugium of detritus?

 

[Jekyl]

Undergravel filter with airstone and 4" pumice plus a top layer of 2" of coral skeletons such as Reborn will not just assist in nitrification of that detritus but will also perform denitrification along with melting those coral skeletons identical to a calcium reactor due to acidification via nitrification. Denitrification will release alkalinity lost during nitrification. Powerhead is going to clog it and that will require maintenance. This will also allow decomposers to break the detritus into elements that the chaeto can utilize. Decomposers being heterotrophic bacteria along with amphipods and copepods that likely already exist in the chaeto. Consider adding nassarius snails to sift the gravel and consume that detritus. Conch might help as well.

Replace the coral skeletons as they melt. Just layer on top since the top layer will be exposed to the highest level of oxygen and conduct the bulk of that nitrification. Let nature do the work. It has for billions of years before we started boxing fish with water.

From what I've heard all standard ugf systems fail at some point.

 

[GARRIGA]

From what I've heard all standard ugf systems fail at some point.

That’s naturally impossible. All that is happening is decomposition. What I believe destroys UF is the constant syphoning because people are told to remove detritus vs just leaving it alone and allowing nature to run it’s process.

Been running UF since the 70s. First salt tank was an UF with four inches of dolomite. No WC. Nitrates eventually settled around 20ppm.

In the 70s I used to take my UF apart thinking they needed to beleaned thoroughly every 3-6 months. Foolish fodder of the 70s. All I ever found was mulm. Never detritus. That mulm will eventually mineralized and release calcium and magnesium along with other elements introduced via feeding. Why food introduced is so important. My opinion.

Ever consider that the mantra behind them failing might be profit driven since for a few dollars one can run a reef tank vs needing all the expensive profit making equipment? LFS make more selling you sumps and skimmer than a lowly UF. Then you need a sulphur denitrator or lighting for a sump to battle what that UF was going to accomplish if setup correctly.

Don’t forget the profits in salt as a method of exporting nutrients. Lots of money in salt as well adding alkalinity that denitrification returns naturally. Pure madness

 

[Spare time]

I think those vacuum attatchments by vca would be really handy for cleaning sumps. I usually just stir it up and have a filter pad before the pump collect some crud or vacuum it out with a pump.


However, the better way to deal with this is to provide better mechanical filtration before the refugium. This isn't always the case though, as some (such as me) have piles or turbo snail feces in their sump to keep the refugium clean of hair algae.

 

[BurgerFish]

@Dan_P when the fuge full of chaeto, it's hard to syphon, also it will remove some pods.

@GARRIGA reverse flow undergravel (feeded by return pump) also works? Without airstone. Pumice is like Seachem Matrix?

@minus9 I have no idea where to get all those critters in Canada... The only thing I got from LFS is aiptasia, flatworms and bubble algaes...

 

[Jekyl]

@Dan_P when the fuge full of chaeto, it's hard to syphon, also it will remove some pods.

@GARRIGA reverse flow undergravel (feeded by return pump) also works? Without airstone. Pumice is like Seachem Matrix?

@minus9 I have no idea where to get all those critters in Canada... The only thing I got from LFS is aiptasia, flatworms and bubble algaes...

No on the return pump. If running RUGF you need low flow. I have a 250g pump feeding 2 plates in my 90g. For a small 12x12 you probably want 50gph, if even that.

 

[minus9]

@Dan_P when the fuge full of chaeto, it's hard to syphon, also it will remove some pods.

@GARRIGA reverse flow undergravel (feeded by return pump) also works? Without airstone. Pumice is like Seachem Matrix?

@minus9 I have no idea where to get all those critters in Canada... The only thing I got from LFS is aiptasia, flatworms and bubble algaes...

All you need to start is spaghetti worms, pods, bristle worms and micro brittle stars. I’m sure there are local reefers who would share some of those with you.

 

[GARRIGA]

@Dan_P when the fuge full of chaeto, it's hard to syphon, also it will remove some pods.

@GARRIGA reverse flow undergravel (feeded by return pump) also works? Without airstone. Pumice is like Seachem Matrix?

@minus9 I have no idea where to get all those critters in Canada... The only thing I got from LFS is aiptasia, flatworms and bubble algaes...

Reverse flow what I would do if using a powerhead. However, faster the flow then more likely the filter will clog with detritus that hasn’t decomposed. Why with UF I prefer air stones or the ability to restrict flow. Were there a DC powerhead then I’d use that but in the conventional manner. Reverse flow based on the premise that detritus can be suspended and exported out. I want to avoid that and just let it decompose and mineralize naturally.

Yes. Pumice is matrix. Minus the marketing. Can be obtain in various sizes from garden supply stores although more likely from those servicing orchid growers. Home Depot sells 1/4” (same size as Denitrate) 20 QTs for around $60.

 

[Dan_P]

@Dan_P when the fuge full of chaeto, it's hard to syphon, also it will remove some pods.

@GARRIGA reverse flow undergravel (feeded by return pump) also works? Without airstone. Pumice is like Seachem Matrix?

@minus9 I have no idea where to get all those critters in Canada... The only thing I got from LFS is aiptasia, flatworms and bubble algaes...

I understand. Here are some thoughts.

Removing all the detritus build up is likely unnecessary. There is a reason the pods make the detritus their home. Consider only a partial removal. Unless you are raising pods to harvest, thinning out their population seems like good animal husbandry.

If Chaeto is making it difficult to remove detritus, you might consider harvesting some of it to keep it healthy. When you pull it out to trim it and rinse it, clean the sump bottom.

 

[BurgerFish]

@GARRIGA so, the flow under UF must be low? And flow in the entire refugium?

 

[GARRIGA]

@GARRIGA so, the flow under UF must be low? And flow in the entire refugium?

Both aren't mutually inclusive. Flow through the fuge can be faster because chaeto is able to process nutrients quickly. The UF favors a slower flow to prevent clogging with detritus plus allow nitrification to remove DO creating an environment consisting of bound oxygen that will be utilized by heterotrophic bacteria along with a carbon source to remove nitrates. I sometimes have to introduce NoPox to lower my nitrates as they usually remain under 5 ppm but sometimes will creep up to 20 and as much as 40 for a day or two. Not sure why but might be due to the media not be mature enough. In the past with just an UF and no carbon dosing my nitrates remained around 20 ppm and I didn't perform WC therefore that was all on the filtration.

To me the UF in the fuge is there strictly to manage the build up of detritus. Therefore, if space is limited and can't provide a thick enough substrate to facilitate denitrification then just trapping the detritus to allow heterotrophic bacteria to break it down into inorganic compounds usable by the chaeto would be sufficient enough in my estimation. Chaeto is going to remove nutrients. I know that with most freshwater plants they favor ammonium and have to convert nitrates to nitrite and nitrite to ammonium. I suspect the same occurs with macro algae but haven't found definitive evidence.

BTW, I'd consider placing the riser at the beginning of the fuge mid way up the water column so the CO2 laden effluent comes into contact with the chaeto which benefit photosynthesis when illuminated and raise PH. One of the drawbacks of biological filtration is the production of CO2 but that can be gassed out or utilized by plants. Might want to also experiment with keeping the Chaeto illuminated 24/7. I've done that with freshwater plants and freshwater single cell algae (phyto) and it worked extremely well. Assuming the Chaeto aren't affected negatively then the only downside is bottoming out nutrients yet I find it easier to dose nutrients and start with a blank base then trying to manage a certain level base on daily cycling of nutrients.