detritus and nitrate questions..

[jiggy]

i have 3 serio 2600s in my 120g as well as a mag 9.5 return.. everyone says that detritus should not settle on the bottom of the tank, but i have a ton of liverock (180+lbs in a tank thats 60lx18wx24h) and some detritus still settles no matter how i adjust the powerheads.. do i still need more flow? or is this ok?

my water params are
salinity: 1.024
temp: 80
ca: 450
alk: 5 mq/l
phosphates: .05 (without kent phsphate remover)
nitrite: 0
nitrate: 50ppm

i havent installed my asm g3 yet.. will the skimmer drastically lower my nitrates? to how many ppm?

 

[redwinger02]

It is virtually impossible to keep it all from settleing you just hve to stay on top of it with siphoning.

 

[redwinger02]

Well get that skimmer going! Where else would the detritus go if your skimmer is not online.

 

[johnvu713]

have you tried Nitrate sponge..some says it works. I just put some in my sump 2 days ago and will fill you in once i get result

 

[elephen]

I second siphoning. Keep your rock setup so you have them most minimal points touching, that way it makes it easier to get under the rock to siphon or blow out the detrius from underneath the rock.

Man 3 2600's in a 120, those take up a nice chunk of real estate

 

[Amphiprion]

I would also keep siphoning. Although nitrates are preferably as low as possible, minimizing detritus will primarily lower phosphate and nitrate to a lesser extent.

 

[MCsaxmaster]

I'd consider getting rid of some of the rock. That much rock will make things difficult long term, no doubt about it.

A protein skimmer can't remove nitrate, but it can remove organic material that could potentially be degraded into nitrate. Many organisms can take up nitrate though (algae, corals, bacteria, etc.) and thereby remove it from the water. I'd do some water changes though as that's pretty high. Maybe try a 25% or larger change weekly and see where you get.

Chris

 

[MCsaxmaster]

minimizing detritus will primarily lower phosphate and nitrate to a lesser extent.

How do you figure detritus contains relatively more P than N?

 

[Amphiprion]

Not really that. Mainly because I figure there is more breakdown of nitrate in some form or another (denitrification) as opposed to phosphate. Actually composition simply depends upon the origin of the matter in question. That is actually what I meant, but my diction was a bit awkward. I would worry about PO4 much more than I would NO3, anyway. An analysis (albeit in freshwater tanks) showed that nitrate could be added in large quantities, however, only until phosphate entered the tank in controlled amounts did algae actually took hold. If you have phosphate as low as possible, a little nitrate (as not everyone, even with WC, siphoning etc. can get rid of it) is not a problem.

 

[MCsaxmaster]

Ha, ok. Agreed :thumbsup:

As a note, in freshwater environments usually phosphorus limits primary production. In marine waters, however, it is usually nitrogen that is limiting, not phosphorus (although iron does in the parts of the southern ocean). For an aquarium to replicate nature, we should be able to dump in phosphate all day long and not see any increase in algal growth. Additional nitrogen should increase production though. However, usually aquariums are a bit skewed as compared to nature, and phosphorus probably does limit production in most aquariums.

Chris

 

[Amphiprion]

Yes, this is correct, I am aware of marine nutrient cycles. But as you said, our puny closed systems closely reflect those freshwater trends. It is a rare aquarium that falls outside this trend.

 

[MCsaxmaster]

Hmmm, maybe maybe not. It would be an interesting thing to measure N and P in a bunch of tanks and see where they're at. Most marine water is between 5:1 and 10:1 (sometimes higher though--N is often a lot higher near rivers). I mean, I've seen tanks before that had detectable phosphate but not much nitrate. Somebody with 0.1 ppm phosphate and say 5 ppm nitrate will be P limited before N. Definitely would be interesting to test a bunch of tanks and see where things fall.

Chris

 

[Amphiprion]

I do all the time. Testing water on a variety of different tanks has reflected this same thing, IME. I usually see the ratio skewed dramatically to N. But these nutrient levels primarily only apply to reefs and certain open ocean waters, not marine waters in general, as much of it has significantly higher quantities of both nutrients, especially temperate and polar regions. Including more phosphate in water will increase growth of nuisance organisms, namely cyanobacteria. Since these organisms are largely able to fix atmospheric nitrogen, excess phosphate will certainly favor their growth. In many "starved" reefs, cyanobacteria present a large problem, often continuing disease processes in the already stressed corals. However, IME, limiting more phosphate than nitrate seems to discourage most algae from even forming (with exceptions of course).