Is My Low Ph Preventing Mini-Cycle Recovery?

[Gvilleguy]

My tank was fully cycled as of June 29, 2010. So I've run two months with fish. Two weeks ago I did a cleaning on my Fluval 205 filter. I was careful to only lightly squeeze the foam media in a bucket of tank water, and I discarded a carbon pack media from the bottom tray and replaced it with pre-filter media. The top two trays have bio-cylinder media. The only way those would have been affected would be getting tilted to drain the water from the canister as I removed items to check them. So they were shifted a bit and not cleaned.

Starting the next day and for two weeks since, my ammonia readings have been 0.25 ppm. My other readings have been consistent every day:

nitrite = 0
nitrates = 5.0
pH = 6.0
KH & GH = 0 (really, really soft)

I do not have a low range pH test kit, so I guess it could be lower than 6.0.

Water changes do not help me here, as my tap water includes (at no additional charge!!) 0.25 ppm of ammonia. So I'm just pouring more ammonia into the water.

I've never had a mini-cycle go longer than about 5 days. Suggestions for helping this recovery move along???

I don't want to buffer the pH with baking soda. That might kick start bacteria production like in a fishless cycle, I suppose, but wouldn't that also cause the fish to feel the ammonia more keenly? Should I purchase some water from the store to get a water change without ammonia? Or just wait this out?

Thanks.

 

[awilson360]

My tank was fully cycled as of June 29, 2010. So I've run two months with fish. Two weeks ago I did a cleaning on my Fluval 205 filter. I was careful to only lightly squeeze the foam media in a bucket of tank water, and I discarded a carbon pack media from the bottom tray and replaced it with pre-filter media. The top two trays have bio-cylinder media. The only way those would have been affected would be getting tilted to drain the water from the canister as I removed items to check them. So they were shifted a bit and not cleaned.

Starting the next day and for two weeks since, my ammonia readings have been 0.25 ppm. My other readings have been consistent every day:

nitrite = 0
nitrates = 5.0
pH = 6.0
KH & GH = 0 (really, really soft)

I do not have a low range pH test kit, so I guess it could be lower than 6.0.

Water changes do not help me here, as my tap water includes (at no additional charge!!) 0.25 ppm of ammonia. So I'm just pouring more ammonia into the water.

I've never had a mini-cycle go longer than about 5 days. Suggestions for helping this recovery move along???

I don't want to buffer the pH with baking soda. That might kick start bacteria production like in a fishless cycle, I suppose, but wouldn't that also cause the fish to feel the ammonia more keenly? Should I purchase some water from the store to get a water change without ammonia? Or just wait this out?

Thanks.

Hey Gvilleguy,

Just curious about what test kit your using as my Ammonia 0 reading using the API test kit has a slight green hue to the yellow which I definately know is 0 but could argue that it looks the same as 0.25ppm. Are the fish showing any symptoms?

AW

 

[PDSimon]

The pH isn't the problem. You could run a tank at 4-5 pH, probably even less and it would be fine. Its only a problem when cycling... not with fish.

Are you adding anything to the tank like ferts?

It doesn't really sound like a minicycle if its lasting for so long... so not quite sure. Are the fish showing signs of ammonia problems? is no nitrite appearing? it should be if the ammonia is real.

dosing things like TPN+ make ammonia show up even though its not actually ammonia

 

[Gvilleguy]

I use liquid API test kit - and ammonia has always shown pure yellow for me.

Interesting - I had no idea ferts could relate to ammonia readings. Two weeks ago is when I started dosing liquid fert once per week for live plants that I recently added to the tank. I'm not familiar with fert types, and there was only one option at Petsmart - it's "API Leaf Zone Plant" - on the back on the bottle is says "Guaranteed analysis 0-0-3:
Soluble Potash 3%
Iron 0.10%
Derived from potassium sulfate and Iron EDTA."

My nitrites have definitely been zero the entire time. So is this likely just a case of "false ammonia"?

 

[OldMan47]

Your label says no nitrogen, no phosphorus and a low concentration of potassium (K). Saying 3% potash is redundant, it already said that in the numbers. It was the 3 in the 0-0-3. The trace of chelated iron means it will stay bioavailable longer and the form of K as KSO4 is typical of what you might mix up using a dry fertilizer supplier like I have done in the past. I'm afraid you do indeed have very low pH for the cycled filter you are working with. The bacteria that we work quite hard to grow do not know where their ammonia is coming from so ammonia in any form is absorbed by them equally well whether in a fishless cycle or with fish in the tank at any given pH. You can eventually get a bacterial colony functioning at a pH of 6.0 but it takes a long time to adapt to those conditions. In the meantime, a very low pH makes ammonia take on the safer form, so it should not be a problem in low concentrations.

 

[waterdrop]

Agree with OM47. GVG I tend to think of your water as like mine up here in Chapel Hill but it appears that yours is even softer and more acid than mine and I think OM's analysis is probably right on the money. You might, out of curiosity do a jar of water with that fert dosed in it and take before/after ammonia readings for the adding of the fert to the jar of tap water.

~~softwater~~

 

[Gvilleguy]

Thanks much for your replies, gents. This Greenville water is a blessing and a curse, I think. I'm going to wait this out, then, before trying anything else. The fish have acted normally this entire time and are not showing signs of stress.

I might do as WD suggests and test does some water outside the tank. I'll report back if/when the bacteria get re-established.

 

[waterdrop]

Oh, just thinking this morning you could serve as yet another data point in my spotty little attempt to see what a Salifert ammonia test would give compared to what your API ammonia test is giving. Unless Greenville has a really unusual shop you'd probably have to order it from BigAls or some other online supply place. WD (and it would be a bit expensive and a bit more trouble to carry out and at some point you'd say "why did WD put me up to this" )

 

[PDSimon]

How long does it take for the bacteria to adapt to a lower pH when you've stocked fish? I initially had problems stocking as my pH crashed overnight when I went to stock the fish the next day from 7.5 - 6.0 but when I sorted that out and stocked, my pH dropped from 7.5 - 6 in days (due to bogwood and my low buffering capacity) and the cycling has been fine. Maybe due to the abundance of bacteria?

 

[waterdrop]

Right, I feel there's a huge difference between the ability of a mature filter to handle various adversities versus an immature filter (thus the various comments here in the forum about maturation as long as 6 months to a year.) ...Any number of reports about the fact that bacteria will eventually recover and operate down in the acid range but not many reports about the timing, I expect it varies. WD

 

[Gvilleguy]

I can attest to having a delicate filter system at 4 months. In spite of cautious cleanings, I still have trouble with the bacteria getting unsettled. I hope once the tank matures it won't be as much of an issue.

 

[Gvilleguy]

Finally, I'm happy to report an ammonia reading of zero this morning!! That took 18 days from the filter cleaning until ammonia dropped back to zero from 0.25 ppm. Assuming the plant fertilizer was not causing any bogus readings (which I will find out this weekend when I add a bit more to the tank), I'm thinking I must have discarded helpful bacteria when I threw away the carbon filter pack. Now that I have pre-filter media in place in that tray, I'm hoping I won't have trouble.

 

[waterdrop]

I know the Fluval 205 is a smallish external cannister filter but I'm actually not that familiar with the internals like the tray layout and size. How big was that carbon sack you tossed? Perhaps we should make a greater effort to encourage that this be done in partial replacements (ie. you take away only one half of the total carbon and then wait a couple weeks, that sort of idea.) I'm on and off about recommending that, but maybe I should try to be more reliable about including advice like that.

WD

 

[Gvilleguy]

For me a picture always helps, so that's why I'm always posting pics on here. The layout of the Fluval 205 is like this:

The canister housing (not counting the pump lid) is about 10 inches tall and about 6 inches wide. So each of those three trays is approx. 6 long x 3 wide x 3 high.

And here is an unused carbon pack so you can see the size - not quite as wide as my hand, but just as tall:

 

[waterdrop]

Yes, the picture makes quick work of clarifying!

And it strikes me right away that that volume of carbon would represent quite a large surface area of biofilms. Losing it all at once would indeed probably have been too much. I'm glad your bacteria have finally made a comeback.

~~waterdrop~~