fishless cycle - dropping PH

[HeatherW]

so I am now doing my second fishless cycle on my new QT tank. thought I knew what I was doing... but now I am having problems.

today is the third day in a row that my PH is low. I have done about a 90% WC every day that I see the PH has dropped - so today was my third big WC. Started out dosing the tank with ammonia, then I added more to get it up to 4ppm. tank is pretty much converting all the ammonia but nitrites are super high. also had super high nitrates, but they are probably lower now that I am doing all these water changes.

so here is my question. what should I be doing? do i need to do enough water changes to get my nitrites back down to readable or should just one big wc be enough to get me back on track. why is my ph dropping everyday?

todays results:
temp 76
ammonia .25
nitrites 7+
PH 7.0 (normal is 7.6)

past 3 days nitrites 7+, PH 7.0, ammonia (0,.5,.25)

 

[jlk]

This just shows you what a difference larger volumes of water make! In this small tank, your buffer levels are being used up quickly thus the ph drop. Its sounds like your on track though with your amm>nitrite bacteria converting everything quickly. Ok, lets try this- do a big water change & retest your nitrites to see if they have dropped. When they get crazy high, it sometimes takes more than one 90+%wc to drop them down to readable (less than 2ppm). Then just add a small dose of amm (1ppm) & see what happens to your ph/amm/nitrite in 24hrs.

 

[HeatherW]

OK, so I did my large water changes yesterday - actually got the nitrites down to 0ppm (or at least I thought I did) after all the WCs. added just 3ml of ammonia - had been adding 8ml the last several days. tested my water this afternoon. ammonia is good - 0ppm but nitrites are back to sky high - at least 7+ppm. good thing is the ph is now holding at 7.6 just where it should be.

so what to do today? dose at 3ml? 6ml? the goal is to add enough that I keep things going but give the nitrite > nitrate bb to work right?

so any thoughts? I was leaning towards the 6ml...

 

[jlk]

Lets do 3-4mls for the next two days & see how your ph holds up before increasing the dose. Your amm>nitrite bacteria will bounce right back when you increase the dose so im not concerned about them. Did you start this tank with any cycled media or are you doing this from scratch?

 

[HeatherW]

I have cycled media in there but not sure it is really making much of a difference.

I added 3 this afternoon. We will see how it goes. So do I stay with this until my nitrites drop?

 

[jlk]

Just for another day or so to see how your ph holds up. Then your are fine to increase the amm dose gradually. I think the cycled media is behind your great amm>nitrite conversion but the nitrite>nitrate bacteria are not quite up to speed yet. Bacteria are such finicky creatures!

 

[HeatherW]

OK, added 3ml this evening - so far so good. ph holding, ammonia at .25, nitrites 7+
i will let this settle for a bit before I bump it up and then maybe just 1ml at a time

 

[jlk]

Sounds good! Just keep track of how long your nitrites are running at crazy levels- if it goes beyond a week, a water change to drop them should help things along.

 

[HeatherW]

So an update on my tank. Finally got the nitrites to settle down. I am now
Ammonia - 0
Nitrites- .1
Ph -7.6 (normal for my tank)

So where do I go from here? Should I start increasing my ammonia dose again? How much?

 

[jlk]

Good job! Go ahead & increase the ammonia by another ml & see how your tank does.

 

[HeatherW]

Wow! It worked!! This gets me every time!! Checked today and we are at 0!! Added 4ml yesterday and then again today. What to do now? Slightly increase every day or every other day until I am at what? I think I want to add either 3 rainbow fish and maybe a Molly in there to qt for about three weeks . What level should I get my tank up to to handle that load? 14 gallon qt tank

So exciting! I am amazed every time lol

 

[jetajockey]

The target ppm that most fishless cyclers recommend is 4ppm, with that fish load I doubt you'll be reaching that on a daily basis. Not sure how many ML that is for your dosing. Either way the biofilter is going to adjust itself based on the fish load, if you go overkill then some of the bacteria colony is going to die off to compensate, and likewise if you add a larger ammonia source than what is being regularly added, the bacteria colony will grow to compensate. So with whatever you do, just monitor the toxin levels after adding the fish for a few days, but the biofilter sounds like it is established enough to adjust itself in short order.

 

[jlk]

Great job, Heather! I honestly dont know what kind of bioload rainbows & mollies carry- you have a better idea than I do! If you want to increase your biological filter, go ahead & increase the amm a bit each day & see how your tank handles it before the next increase. If everything stays stable, it only should take a day or two for the bacteria to readjust with each increase. When you get things to where you want them to be, you already know the drill on prepping the tank for fish. I truly wish you luck with your newest aquisitions & hope they healthy (and stay that way!)!

 

[HeatherW]

Just thought I would update. Got my tank cycled! Yay! I just slowly uppedy ammonia by 1ml every 2 days- it kept going to 0 but I didn't want to shock anyone.

Got me one dalmation Molly in there and 5 Otos. So far so good. Tank is holding steady. Molly doesn't seem to be eating lots which I find strange considering all my other mollies are little hoovers. Keeping an eye on the Otos - a little worried about them because of all I have read about them not eating pellets. We will see.

I plan on adding 3-4 rainbows in there next week. My fish store guy said he would order some more for me. This is my qt tank and plan on keeping these guys in here for about 3 weeks

 

[jlk]

Thats great, Heather!! Congrats! I honestly would aim for atleast 4wks for qt- 3wks seems to be the magic number for when issues rear their ugly heads. We dont want any repeats of your last adventure! Good luck!!!

 

[HeatherW]

sounds like a plan! besides - the tank they are going to go into is still a mess! I use carbon to clean out the meds in a few days but I still am kicking out low levels of ammonia and now low levels of nitrites. I am monitoring daily hoping that I can push it just another day and then I will add the carbon and start doing water changes. My fish will be so happy. can't wait to have a clean healthy tank again.