Plenum HELP-Stay or go?

ONEWAY

ONEWAY

Premium Member
Hi everyone, I have a 120 gallon sps tank running with the berlin system and a plenum. It has been up and running for about four years, full sps about 2 1/2 years. I currently dose prdabio and it's been doing well bet I think I am being hurt by my plenum. I havent been able to drop my nitrates down to what they should be 0. After a slight laps in missing a few doses I noticed a few of my sps starting to rtn so I did the standard water parameter tests to find my nitrates jumped up high so high I am imbarresed at what they went to at just about 100 all other peramiters are good. But I have no hair or red slime alega. I cant seem to be able to get it down. So should I bite the bullet and pull the plenum out. Here are some pics all in all things are doing O.K.

Thanks,
Anthony


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My first question is how old is the nitrate test. The corals look too good for nitrates to be that high.

How large is your substrate? Can detritus be caught in it?
 
My test kit is slightly on the olderside but I confermed the results with my friends test kit which is farly new. When things are off in terms of water testing I always double check with other test kits before doing anything. It was high even even with his test kit. Right now I have courser substrate on top not by choise but due to the flow in the tank bringing up the courser. Also I tryed to have minium rock on the sand to prevent dead spots. I also stir my sand up every so often. The tank overall is doing well and its hard to tell from the pics the rtn that is going on the only thing that is high is the nitrates.


Thanks
Anthony
 
I helped a buddy with his 120 gallon tank. Same problem - Nitrates. It worked, and also allowed him to get a little creative with the aquascape since EVERYTHING has to come out. He didn't have SPS to your extend but it was the same situation.

Of course you know what to do to remove everything, but being prepared first is key. The faster and more efficiently you can do everything, the better off your tank's inhabitants will be. I recommend HUGE rubbermaid containers with powerheads in each, and saving as much water as possible. You will unavoidably lose water (and a slight PH drop no doubt) along the way, but the best scenario will result in the effect of a simple water change. You don't want to kick-start a new cycle.

I also recommend those super thick latex gloves for reefing... not seeing where your hands go and grabbing large bristle worms hurt like heck. Same with spiny inverts and just sharp rocks. Your instinct reaction is to drop what you're holding and you don't want to drop a prized Acro colony.

Other tips:

- Disturb the plenum as little as possible, even when taking out the substrate. Syphon out the crap when the water is almost all out and try to get all of it!
- Remember to turn all pumps off while working in the tank. Having water shoot across the room is not fun to clean up.
- When you turn pumps back on, you may get air pockets that keep water from flowing properly. Don't panic, just get a bottle brush (The actual brush, not your Acro lol) and try to work out the bubbles. Or pour water down the lines to help in the priming of the pumps.
- Keep razorblades handy for coraline you might not have been able to scrape before
- Don't let the cat or dog in the room if you have one
- Lots of towels!
- Get some fellow reefers to help you. 3 or 4 of you working together will help the process go smoother and keep you from losing your mind. And trust me, you will have a few laughs along the way too. It's YOUR tank and you're way of doing things, but even noob's can have creative outside the box ways of doing things that a seasoned reefer might not.
 
Thanks fishguy84. So thats one for taking it out. I think I'm leaning more to taking it out I can't think of anything else keeping the nitrates up.
 
It's a great idea, and has been used with success, but it's essentially a cesspool under your substrate. Yes there's bacteria that will work, but they need to get emptied anyway. Just like a port-o-potty. Bacteria can only eat at a certain rate. I don't have a study to prove my theory... but whats the point of keeping ANY poop in the tank?
 
There was an advanced aquarist article that found no difference between the plenum and no plenum system. I can dig it up here in a few

I would vote for removing it as well. I have run a few non-plenum DSB and they have their uses for denitrification, but for a SPS heavy system like yours I would really lean towards an easy to clean SSB or BB if you can stand the looks.
 
Yea, I think I'll be pulling it out. But I hope this is what is contrubiting to my nitrate problem. Thanks for all your help thus far, any other imput is greatly appreciated.
 
It's a great idea, and has been used with success, but it's essentially a cesspool under your substrate. Yes there's bacteria that will work, but they need to get emptied anyway. Just like a port-o-potty. Bacteria can only eat at a certain rate. I don't have a study to prove my theory... but whats the point of keeping ANY poop in the tank?
Click to expand...

I think that's where the misconception comes in concerning Plemums. I ran one for 3 years & vacumed it on a semi-monthly basis...........which is what is required maintenance according to Bob Goemans. I also set up my plenum to his specific design & maintenance, which is VERY important for success.

I never had a nitrate or phosphate issue & when I took it down the substrate was spotless. There was absolutely no dirt or detritus in the substrate. These are unlike a DSB where, if you follow Shimek, the bed should'nt be disturbed & becomes a septic tank over the years.

I never understood why people can't or won't make the distinction between a plenum & DSB. They aren't the same or maintained the same. They also use different sand sizes........another important aspect of a plenum for success. That's why I have a big probmem with that Advanced Aq. article that Jenglish posted. It's complete hogwash on so many levels.........one of which is trying to run two systems the same way that require different rules for maintenance.

Anwyways, in reference to your problem ONEWAY........if you haven't kept up a regular schedule of vacuming the bed I'm not suprised you are having nitrate problems.

My one question is.............were you having problems with recession before you started the prodibio? It wouldn't hurt to take the sand out.

You say you missed a few doses & blame it on the plenum? Not sure that makes sense.
 
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Big E don't get me wrong I'm not blaming the plenum but like you said it has to be set up and maintained correctly. In my opinion the plenum is old school not that it does not work but there are easier ways of keeping a low nutrient system and the tank has to be set up for it. With the Prodabio I was able to keep my nitrates in somewhat control. But the plenum I think is hurting be rather than helping.


jenglish-Jeremy great artical thanks
Thanks
Anthony

lets keep this going
 
Big E said:
I think that's where the misconception comes in concerning Plemums. I ran one for 3 years & vacumed it on a semi-monthly basis...........which is what is required maintenance according to Bob Goemans. I also set up my plenum to his specific design & maintenance, which is VERY important for success.

I never had a nitrate or phosphate issue & when I took it down the substrate was spotless. There was absolutely no dirt or detritus in the substrate. These are unlike a DSB where, if you follow Shimek, the bed should'nt be disturbed & becomes a septic tank over the years.

I never understood why people can't or won't make the distinction between a plenum & DSB. They aren't the same or maintained the same. They also use different sand sizes........another important aspect of a plenum for success. That's why I have a big probmem with that Advanced Aq. article that Jenglish posted. It's complete hogwash on so many levels.........one of which is trying to run two systems the same way that require different rules for maintenance.

Anwyways, in reference to your problem ONEWAY........if you haven't kept up a regular schedule of vacuming the bed I'm not suprised you are having nitrate problems.

My one question is.............were you having problems with recession before you started the prodibio? It wouldn't hurt to take the sand out.

You say you missed a few doses & blame it on the plenum? Not sure that makes sense.
Click to expand...

I think that there are a few key points in the article to consider, one being that it was an experiment of maybe a season, not 10 years. Some of the issues differ between sand bed methodologies are not going to show up in 115 days.

Also Toonen has a known bias against plenum, some of his articles he cites that he authored give this away. That is nothing against him, everyone has bias of some sort, even scientists are human.

The real point at least for me was that all the substrates showed some denitrification, a real shocker for the SSB.


I personally have my doubts about the benefits of the void. But my non-plenum DSBs are not ran in a Shimek fashion, more like Goemans w/o a void. THere is plenty of critters in them but they poop too so I siphon the thing regularly. :bigeyes:
 
Hi Jeremy,

I agree.........some of the points you mentioned were a few reasons why the test was bogus.

I couldn't get the link to work for me, but if I remember correctly they come up with some ridiculous conclusion at the very end bashing barebottom setups. It really showed their ignorance/bias.

ONEWAY,

Go for it & take it out if you feel that way.............it won't hurt & could help. Imo, sand is good for looks & animals that need it, but as far as a filtering mechanism it's very limited & there are better ways.
 
ONEWAY said:
Ed I'm not going bare bottom, it will be a shallow sand bed. I need some sand in the tank.
Click to expand...

OneWay....

By now u have taken it out right ??? I just caught this thread and I was wondering what u found "under" your last screen (the actual plenum) If u where fairly careful in removing the top sand and gunk I bet this area was almost spotless.......if not being invaded by critters, I mean stirring up the top area is fairly harmless as long as the area right above the plenum is not.

For what it's worth I have running a 70 gal for over 15 YEARS (for the most part FOWLR) and when nitrate got out of hand it was due my poor maintance and NOT the setup....

the Big E is spot on ....Bob G now does recommend that the Plenum by setup in separate tank tied to the main....Reason.....most folks cannot or willnot due the required maintenance for the in tank plenum....

I NOT trying is refire up the barebottom vs plenum:blown: or any one else I just along my first hand and works for me...

Dick
 
Hi slatydog64,

I agree with the guys, the tank has to be set up and maintained for a plenum and has to be done. I have a situation in my tank now and am also not trying to turn it into a plenum vs bb vs dsb vs ssb by no means. I wanted to know if my I guess not maintained plenum is adding to my problem I cant pinpoint where else it may be coming from Just looking for some good direction, advice and suggestions. As to pulling the plenum out I did not do that yet I will probably pull it after the new year so I can have it well planned out and extra hands on deck. But here are some pics from underneath the tank looking up at the plenum you could see the PVC spacers. I don't think it looks that bad.

Anthony

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