[dinor2]

Well, after 6 months, I finally found where all my nitrates are coming from... my overflow! I have a DAS reef ready 55gallon tank that's a few years old, and the inlets are only at the top, i'll include a picture of what i'm talking about.

http://i219.photobucket.com/albums/c...2/P1039905.jpg

I see reef ready tanks with overflows that have inlets at bottom, middle and top, I wish mine had all three now! Since there is hardly any water flow going from one side of the overflow to the other, where my mj900 puts it back into the main tank, a lot of gunk settled at the verrryyyyy bottom of my overflow, which is hard to see since my lights don't light up my overflow! And even with some rubble live rock down there, there's still a bunch of crud. I discovered this crud when I decided to try something new, I took my turkey baster and, instead of suctioning out water from my overflow, I FIRST squirted water down into the overflow a few times and guess what? All this crud came rushing to the surface of the water! Then, I suctioned just a few turkey baster fulls of water from the overflow and spit it into the main tank, fully realizing that, if this was indeed my nitrate factory, my nitrates would sky rocket. And, next day, they did! My poor blenny is very unhappy so i immediately tested for nitrates, they're so high i'm embarased to put the number up here so needless to say, I did about a 6 gallon water change, 2 gallons from my overflow first.

Here's a pic of a top view of my overflow, the side at the 'top' of the picture , before the blue slat, is where my nitrate factory is!
http://i219.photobucket.com/albums/c...2/P9168279.jpg

My blenny is already starting to breath a little slower after finishing the water change. I'm going to test for nitrates again tonight and post the new results then but I now know where it was the nitrates were coming from.

I only share this because I am betting that someone else may be going thru high nitrate issues like I was; if you have an overflow, especially with inlets at top only, try what I did, pushing water down into the overflow forces any crud settled at the bottom to come up, which lets you get as much out of the tank as possible. Hope this is helpful to someone else, I am relieved to have finally found my nitrate factory.... and so are my fish!

[pogodzib]

Most overflows have some type of standpipe in them so they are only pulling water from the top of the overflow box. This is actually a good thing because the skimmable organics are usually by the surface. It is recommended thought that periodically, you vacuum out the waste that settles in the overflow box.

[combs44]

I stir my overflow regularly for this reason. My overflow turned into a bubble algae and aptasia refuge after I got my emeralds and peppermint shrimp. My display is free of both, but the glass in my overflow is covered with both.

[joelq]

Anyone stick a small powerhead (like the MicroJet) in there just to keep the water constantly stirred up? Or would that be overkill?

[combs44]

It couldn't hurt IMO.

[dinor2]

I plan on doing that as well, I'll have a mj1200 but that may be a little much, not sure. Something else I've determined is that I do not have enough flow towards the back/middle of my lr. As I understand it, nitrifying bacteria need oxygen to live, so, I'm guessing I may be low on those since I have a good sized dead spot in my tank.

So.... I plan on getting two more koralia pumps, another #3 and a #2, the #2 will be at the back of my tank pointing towards the caves and lr at the middle of the tank, and I'll have a total of 2 #3's along with 2 mj1200's and a mj900.... I would THINK that'd be enough flow, but, going to also move around my new koralias and hopefully get them in good spots to create better flow. My mj's are great, but, they won't stay stuck where I put them! I love the koralia!

Oh, cleaned out most of that stuff in the overflow too, not noticing too much of a decrease in nitrates though which lead me to the above theory...

[dinor2]

Ok, check this out! The more you google, the more you learn! Nitrogen Cycle

So, I will not be adding a pump to my overflow since nitrate eating bacteria need anerobic conditions to accumulate, and I am not quite as worried about the lower flow areas in my tank in general now. If anything, I'll put one more 25lb bag of sand in there for a total of 4 inches but maybe not since I know my low flow areas are mostly in the cavework in my lr.... and that's supposed to be a great place for those bacteria to multiply too. And I'm not blowing the lr nearly as much as I have been, it's best these low flow areas are not disturbed so the bacteria can thrive....

Going to feed my fish only what they need to survive until these nitrates get to be at lower levels, preferrably 0!

Anyways, just wanted to share that information I found, very interesting. Seems like most bacteria need that good water flow to thrive, and the ones that consume the nitrates need little to no flow to thrive!

And it took me only 6 months to learn this about the nitrogen cycle....

[joelq]

So basically doing a DSB in the overflow? Interesting.

[dinor2]

Well, no, I'll still keep the overflow relatively clean at the bottom, but I am not as worried about it as i was before. I have between 2-3 inches of sand in my dt, that's where i'm adding the 25lbs of sand to get me 4 inches. I guess if you don't have sand sifting critters that maybe less than 4 inches would be ok but, I've got 7 or 8 nassarius snails who are digging thru the sand constantly. But they usually only go about an inch into the sand, so, adding another inch should give those nitrifying bacteria more room to thrive in that sand. Which makes sense when I think about it, just never really understood what those 3 kinds of bacteria need in order to thrive and thus completing the cycle! So really, there needs to be someplace in the tank for those anerobic bacteria, the deeper sand just seems the better more efficient way to give them that.

So, the nitrates weren't from my overflow, if anything, that stuff settling at the bottom gave those bacteria a place to eat the nitrates, since it's not disturbed at the bottom... so far, ammonia and nitrites read 0 still so, excited to get this figured out and FINALLY have my tank finish cycling!