New tank, new fish, surprising test readings

[elmonty]

I have a new 29 gal tank. It was filled last Monday. Over the past few days, I did a couple of water tests and the results were fairly consistent:

pH=8.0
KH went from 4 to 3
GH went from 7 to 9
Ammonia=0
NO2=0
NO3=0

Last night (Thursday), I put in two gold gouramis, two paradise fish, and some Anacharis plants. This morning I did a water test. I expected to see some ammonia, but I was surprised with the results:

pH=7.5
KH=3
GH=8
Ammonia=0
NO2=0.3
NO3=12.5

These are readings I would expect from a fully cycled tank. I have not added any chemicals other than AquaSafe dechlorinator -- and that was when I filled the tank on Monday. Why would I get these readings?

 

[BrianNY]

Very strange (except for the PH), what kind of test kits are you using? Many that test nitrates are unreliable at the low end.

The PH will waver a bit until the tank becomes established. Do you have any driftwood in the tank?

 

[elmonty]

My test kit is TetraLab, recommended by two good LFS. And yes, I have a large piece of driftwood in the tank. I'll be taking another reading Saturday morning.

 

[elmonty]

This morning I got the same readings as yesterday:

pH=7.5
Ammonia=0
NO2=0.3
NO3=12.5
(GH and KH not tested)

 

[BrianNY]

I'm gonna go out on limb here and say your nitrite and nitrate readings are inaccurate.
Most test kits can't really detect very low concentrations of either. Also, in order to fully understand what's going on with your PH, you need to know what your KH and GH are. One of the reasons your PH may be dropping is because you have fairly soft water.

 

[BrianNY]

Oh, one more thing elmonty...........I'd be very surprised if that ammonia spike didn't show up in a couple of days.

 

[An t-iasg]

I just read an article in Aquarium Fish magazine, April 2004 issue, that says a new, planted tank may throw off typical tank cycling, in that you won't see the ammonia spike, followed by the nitrite spike, and then the appeaance of nitrates. The plants will use the all these wastes faster than they are produced, if the light and CO2 is right.

Did you put a lot of Anacharis plants in? How big are the fish now? Four fish in a 29 gallon doesn't seem like a lot either. So like BrianNY said, your ammonia spike could show up in a few days, when the fish eventually produce enough, or the plants, if you have a lot, will just use the wastes faster than you can track the ammonia and nitrite spikes with your test kits. The test kits may be accurate -- another thing that the article mentioned was that the low levels of the wastes in a planted tank may not be measured by "hobby-grade" test kits.

 

[elmonty]

Thanks An t-iasg, that makes the most sense. However, it is still odd to see NO3=12.5 so soon. The 4 fish are all about 1.5 inches long, although they are eventually expected to grow to 4 inches. I realize the tank can handle more fish but I am trying to be careful while getting the tank cycled.

There are 6 stalks of Anacharis. They are already starting to look yellow at the bottom tips, so tomorrow I guess I need to go out and buy some Flourish. Maybe there aren't enough fish to feed the plants.

 

[medge00]

driftwood can lower your ph.

if you have a good lfs, thats not too far away, try taking your water in to be tested every few days. then compare to your test kits. my lfs is pretty good about this. i take my water in every few months just to be sure i'm on track with everything. this is how i found out my kh test was bad.

 

[elmonty]

I have a large piece of driftwood, but the pH didn't change until the fish and plants were added. I have a Petco nearby that will test my water.

 

[An t-iasg]

I think the nitrate reading of 12.5 is odd too. If the plants are yellowing, and the fish weren't producing enough waste for them yet (because the fish are still small, maybe) then I would expect the nitrate to be closer to 0 (or at least a lower number than 12.5). I agree with the others that getting your water tested at the lfs is a good idea too. I also agree with your decision not to get too many fish, too fast.

 

[elmonty]

Here it is a couple of weeks later, and my water readings are still the same.

pH=8.0
GH=8
KH=2
NH3=0
NO2=0
NO3=12.5

I now have 6 fish in the tank (see my sig). All seem to be doing well. The plants stopped yellowing since I put a new bulb in and added some plant fertilizer (only once so far). In fact, the waterweed is growing like gangbusters.

 

[An t-iasg]

Hi elmonty,
Sounds like you've found the perfect balance between fish and fertilizer, and the tank is stable! What kind of bulb did you get?

P.S. I like your avatar! 8)

P.P.S. Thanks for the kudos!

 

[William]

The only problem is, that most LFS that I've seen.. Do nothing more than pull a test kit off the shelf and use that.


So unless your test kit somehow got contaminated, The results are usually the same.

 

[elmonty]

I think the bulb is an Aqua-Glo 20W 18000K flourescent.