Removing DSB Fuge

[shandy_say]

Hi! Im thinking about removing the DSB in my sump fuge. Im planning to cure some additional LR in a separate tank and once those are cured will disconnect my sump and main tank and then completely remove the dsb in my fuge and add some more LR in the sump to replace the dsb. Do you guys think that this is ok or will this crash my system? Hope you can give me some advise!

Thanks!

 

[koranAngel]

interesting qs
ill tag along

 

[Reefers4U]

perhaps remove a little at a time? Do you have a great skimmer? I can't see this being a big issue. As if you were removing a live rock. Do you have a bare bottom display?

 

[shandy_say]

Wouldn't removing it a little at a time release ammonia into the tank because it gets distubed? If i remove the dsb all at once while the main tank is disconnected from the sump, and completely wash the sump and then put it back with the additional LR and newly mixed saltwater, that would lessen the chances of crashing my tank right?

I have an oversized skimmer rated for 200gals while my total water volume is about 100gals. My DT has about 1/2 inch sand in it.

 

[Kolognekoral]

you shouldn't have any problems with ammonia or nitrates coming into the system. A DSB reduces these extremely quickly. If you simply cut it off and remove, make sure you are able to step in to reduce nitrates, which will certainly jump. Is there a particular reason why you want to remove it? They are generally more efficient than LR. What kind of fitration do you run?

 

[Allmost]

only Issue would be the sudden drop in number of denitrifying bacteria and a jump in no3, although if you have other means of nutrition export, it wont make that big of a change.

I did this once for my smaller tank, (the fuge actually broke so had to be removed) the no3 had a sudden jump, some algae bloom, but went away in matter of days and I reduced feeding.

if you have sand bed in main tank, Id try to get out as much as worms and pods or whatever else that lives in the sand bed and put them in the main tank.

 

[elegance coral]

Hi! Im thinking about removing the DSB in my sump fuge. Im planning to cure some additional LR in a separate tank and once those are cured will disconnect my sump and main tank and then completely remove the dsb in my fuge and add some more LR in the sump to replace the dsb. Do you guys think that this is ok or will this crash my system? Hope you can give me some advise!

Thanks!

If your display has plenty of LR, you shouldn't have any problems doing what you describe. You could take the "sump fuge" off line, clean it completely out, hook it back up without adding anything to it, and you shouldn't have problems. If the sand bed is old and/or dirty, your nitrates may actually go down.

 

[shandy_say]

you shouldn't have any problems with ammonia or nitrates coming into the system. A DSB reduces these extremely quickly. If you simply cut it off and remove, make sure you are able to step in to reduce nitrates, which will certainly jump. Is there a particular reason why you want to remove it? They are generally more efficient than LR. What kind of fitration do you run?

I don't think its doing much to reduce nitrates in my tank and i have been vodka dosing my tank but recently stopped as some of my acros experienced STN. It has been said that Vodka Dosing and DSB's don't really mix and if i keep on vodka dosing while having the DSB fuge, it would take too long before the vodka dosing starts to reduce my nitrates. Im currently running a DSB fuge, an oversized skimmer, cheato, phosban, carbon and LR in sump. I was dosing MB7 for quite a while but i have run out of stocks and been unable to purchase it here since the LFS that carries it doesn't have stock yet.

only Issue would be the sudden drop in number of denitrifying bacteria and a jump in no3, although if you have other means of nutrition export, it wont make that big of a change.

I did this once for my smaller tank, (the fuge actually broke so had to be removed) the no3 had a sudden jump, some algae bloom, but went away in matter of days and I reduced feeding.

if you have sand bed in main tank, Id try to get out as much as worms and pods or whatever else that lives in the sand bed and put them in the main tank.

This is why im planning to cure some additional live rock in a separate tank which i will use to replace the lost denitrifying bacteria during the dsb removal. Im just not sure if it will be enough to compesate for the lost bacteria though.

Right now I have an average bioload. My fish list are as follows:

1 PT
2 Banggai Cardinals
2 True Percs
1 Royal Gramma

I feed a 1/2 inch cube of DIY food a day only to my fish. Im not really sure if this is causing the nitrates in my tank as my fish consume all of it within 5 mins only so not much is wasted. You think I should just feed my fish every other day instead of everyday? I actually feed less now that I did before because i used to have anthias that required frequent feedings. But I lost them when I reduced the feeding to 1/2 inch cubes 1x a day.

I don't have much algae in my Display tank however much of the algae grows in my in-line frag tank which is making my frag tank look more like an ATS/Algae fuge. Heheh

If your display has plenty of LR, you shouldn't have any problems doing what you describe. You could take the "sump fuge" off line, clean it completely out, hook it back up without adding anything to it, and you shouldn't have problems. If the sand bed is old and/or dirty, your nitrates may actually go down.

My tank has been online for about 7 months total. 3 months cycle and 4 months with LS. I don't have much LR in my DT as i keep a minimalist scaping. This is actually one of the drawbacks of having a minimalist scape. Most of my LR are in my Sump.

 

[Kolognekoral]

OK, I understand what you are planning. You're right, a DSB is not easy with carbon dosing. As the tank is so young, I would just remove it. As there are LR established in the main tank, you should have no problems. If you are planning on going full carbon dosing, you want to remove the PO4 reactor. It will compete with the bacteria.

As with any change, you need to monitor water quality until everything is stabilized again.

 

[shandy_say]

OK, I understand what you are planning. You're right, a DSB is not easy with carbon dosing. As the tank is so young, I would just remove it. As there are LR established in the main tank, you should have no problems. If you are planning on going full carbon dosing, you want to remove the PO4 reactor. It will compete with the bacteria.

As with any change, you need to monitor water quality until everything is stabilized again.

I actually shut off the reactor when I was dosing vodka into the tank as phosphate readings went completely 0 using 2 test kits (elos and api). But now i turned it on again as i have stopped vodka dosing.

Will give it a couple of weeks to cure some additional LR in a separate tank before I take out the DSB. Thanks for the advise!

 

[AtomHeart]

Just did this in my tank. Have a 120 gal main dt with a 45 gallon sump, about half of which is my refugium. I didn't really realize I needed to be maintaining the DSB so it had developed a half inch of detritus and a patch of black hydrogen sulfide. I isolated the fuge and removed it to prevent the hydrogen sulfide from crashing my tank. Sadly my nitrates have gone from 0 to 25 mg/l in three days without the DSB even as filthy as it was. Tonight I'll be putting back a new fresh DSB and keeping it's top layer clean and maintained this time. Hopefully in a few weeks my nitrates will be back to zero.

 

[shandy_say]

I see. Haven't removed the dsb yet since i still have to get some LR and cure them in a separate container. Some other local reefers here don't have DSB's in their fuge and they only put in LR's in their sump and they have 0 nitrates. Still don't know what is causing the nitrates in my tank. I feed even less now and we'll see how that goes while Im curing the LR in a separate container.

 

[perrl]

I slowly removed my DSB by vacuuming of the top layers while doing water changes. I took me a few months to get it all done but I had no problems at all.

 

[ruprecht]

This is why im planning to cure some additional live rock in a separate tank which i will use to replace the lost denitrifying bacteria during the dsb removal. Im just not sure if it will be enough to compesate for the lost bacteria though.

Typically, the majority denitrification occurs anaerobically. Also, the amount of surface area available to bacteria on live rock is by no means comparable to that of sand. Your skimmer wont remove nitrate and if you have a healthy supply of chaeto nitrogen is obviously in abundant supply.

Removing your DSB sounds like a horrible idea.

 

[shandy_say]

Right now I haven't been able to remove the dsb yet. Been dosing mb7 and vodka these past few days and so far the nitrates have gone down from 20ppm to 10ppm. Lets see if it goes down to 0. If it does, then maybe i don't have to remove the dsb. Comments?

 

[ruprecht]

What's the source of your water changes?

 

[shandy_say]

I buy RODI water from a water refilling station and use Red Sea Coral Pro saltmix. Already tested it for no3 and po4 and both are 0ppm.

 

[ruprecht]

How fast does your chaeto grow? How often do you harvest?
How much dead plant material is in your refugium?
How deep/big is your DSB?
70 gallon tank? How much water is over your DSB?
How much flow over the sand is there?
Do you have worms or other burrowers live in your DSB?
Are there bubbles in your sand?
Do you have light on your DSB?
Does your skimmer skim before it goes into refugium?
How much/how long are you/have you been dosing vodka?
Can you test for ammonia?
What other livestock is in the tank?

Something is not right. Process of elimination....

 

[shandy_say]

How fast does your chaeto grow? How often do you harvest?
It doesnt grow that fast. 1x a month pruning/harvesting.

How much dead plant material is in your refugium?
None. A little detritus on top of the dsb.

How deep/big is your DSB?
Its about 18x18 with 6 inches of sand.

70 gallon tank? How much water is over your DSB?
about 6 inches of water and LR is on top of the DSB.

How much flow over the sand is there?
A lot. Not really sure how to answer this question.

Do you have worms or other burrowers live in your DSB?
No worms. I have a couple of brittle stars in the dsb/LR fuge. But they don't disturb the sand.

Are there bubbles in your sand?
No.

Do you have light on your DSB?
Yes. I have a 28watt CFL retrofit on top of the Dsb fuge.

Does your skimmer skim before it goes into refugium?
Yes but only about half of the water. One of the overflow pipes from the DT is plumbed directly into the skimmer while the other goes directly to the sump.

How much/how long are you/have you been dosing vodka?
About 2 months.

Can you test for ammonia?
No Ammonia in the tank.

What other livestock is in the tank?
SPS, LPS, Softies, 1 PT, 2 Banggai, 2 True Perc, 1 Royal Gramma, 2 Starfishes, about 10 astrea, and 10 nassarius.


Something is not right. Process of elimination....
Can't seem to find what the problem is. My best guess is the DIY food. Hence i have been feeding a lot less now.

 

[ruprecht]

I'd guess it's your skimmer not skimming all the water, and the detritus that's settling on your DSB surface. It is possible that you are not getting enough bioturbation in your refugium either. You dose, the bacteria bloom, eat nitrate, they die, then settle on sand, mineralize, into ammonia, gets turned into more nitrate, sand is clogged, nitrates can't diffuse to low oxygen sediments to get converted to gas, and/or maybe the bottom sediments are anaerobic and instead of N2 they are making ammonia and thus feeding the nitrate again. Your chaeto can't grow and thus remove the nitrate because you're taking out all the phosphate with your reactor. I don't think the rocks on your DSB are helping anything. You want good flow over the sand and no dead spots to prevent diffusion and pore water circulation. There also may be nitrate leeching out of your rocks too. 10-20 ppm really isn't that bad and I doubt it's having any negative short term effects on your critters. I can't see that driving your acro to necro. Stick with it, you'll figure it out soon enough.