High Nitrates

[Decz]

I moved one of my tanks, my 20 gallon high to my new place, about 6 weeks ago. All the same fish, same substrate, same plants. New rocks. After 4 weeks, some of my serpae tetra's (whom I have had for over a year), started showing signs of some sort of infection/fungas. Honestly, it almost looks like he's rotting away the way a salmon does during spawning. He started getting this white patchy stuff on him, now, added to that, he has black patchy stuff. He hangs out in a cave (not normal for him), and doesn't really come out. And his fins are starting to show signs of either nipping or rot.

When I moved, I was very careful to keep the substrate (sand) wet, as well as my plants and filter media. I did not move much of the tank water, only enough to move the fish, and that water wasn't even put in the tank when it was set back up, I started all over with new water.

I've tested my water, almost daily, and the nitrAtes just keep skyrocketing. This has been going on for 2 weeks now. I've done 5 huge water changes to lower the nitrAtes. almost 80% at one point, but mostly 60%. When I do the water change, the nitrAtes do drop, but are still readable on the chart (Hagen test kit).

Currently:

PH 7.4
KH 4
GH 3
Ammonia 0
NitrItes 0
Nitrates between 50-110 mg/L (which is the max reading on my chart)


* NOTHING else changes, only NitrAtes.... ????

I assume that the nitrAts are causing my fish to be ill. Many others in the tank are also showing some pretty sickly signs. Sorry, don't have a camera to get some pics on here...

Also, there have been no fish deaths, and I tested my tap water and there are no nitrAtes present. The only difference between my tap water and tank water is the PH. tap comes out at 6, so I use crushed coral in the filter to raise this. I use Prime, so chlorine and chloramine are non-existent.

1 RTBS
1 Spotted raphael catfish
4 Serpae tetra's
3 Cherry barbs


Anyone have any idea's what is raising my NitrAtes like this? I'm not even sure how to treat these guys, besides the drastic, by-daily water changes.

None of my other tanks are going thru this, and they all were moved at the same time.


Anyone?

Thanks, Decz.

 

[famman]

Some on this board have disagreed with me, however I believe that after a long period of time, NitrAtes and some NitrItes can settle in substantial concentration in your substrate in non heavily planted tanks. My hypothesis: When you moved your tank, you stirred up this reserviour of nitrates (solids? dense liquids?).

I had a very similiar episode with my 20 gal high after I had fishless cycled it. I had a major NitrIte spike after I added my fish. By mistake I broke it down, washed it and reassembled it. Fortunately my fish survived the brief mini-cycle because most of my culture was on the untouched biowheel, and I changed a lot of water.

Another hypothesis that I considered that would account for the facts (I just looked at my fish diary), was that the Ammo eating bacteria preferentially takes up room on the good media (e.g. biowheel), leaving the less robust NitrIte eating bacteria to take up less oxygenated zones such as your substrate, ornaments etc. During the move, you stressed this colony. In my case the nitrite accumulated until the disturbed nitrite eaters caught up.

If this were the case, a thorough gravel cleaning only water change or two should alleviate the problem. You might also reduce water circulation to allow the nitrites and nitrates to settle.

Just my 2cents worth
good luck

 

[Decz]

Cool, thanks... Just how does one do a thorough cleaning of sand, without taking the entire tank apart?

 

[Decz]

I just did another 75% water change, my nitrAtes are still high. Is it possible that my rocks are raising it? Can't think of anything else..... ??

 

[RTR]

Either your substrate, your filter(s) or the rocks - but I've never heard of rocks with soluble nitrates - are serving as a reservoir. Have you rinsed you filter media (in treated water) ?

What is the nitrate content of the tap water?

 

[Decz]

Yes, I have rinsed my filter media (sponge) in tank water. I do this weekly with regular water changes. I also use filter floss, that I throw away and replace weekly. I will try rinsing my filter sponge in just a bucket of treated water, not tank water, and see if that makes a difference.

As for the sand, it was removed form the tank for the move, and put in a small cooler with a light layer of tank water.



The nitrate content of my tap water is 0. Nothing shows up with my test kit.

 

[wayne]

I believe that for sure if you aren't keeping a deep substrate really clean at some point you'll get nitrate, and possibly phosphate problems, then in alkaline/hard water a blue green algae attack. If you have a sand substrate this will happen more quickly as it's so hard to keep clean. I have had it happen to me - you do a water change, but pretty soon (almost immediately)nitrate/phosphate is diffused from the substrate back into the water.
My advice - thin out the substrate, or break down the tank and clean it. If you don't have plants I'm rapidly starting to think a thin substrate is the way to go.
I have no experience, and thus have no opinions on what thickness substrate to use with UG filters