2 Weeks Into Cycle And Ph Dropped

I've been doing a fishless cycle for 10 days and it was going pretty textbook until this morning. I usually test my parameters in the am as soon as I get up (is this the right time to check? Should I test in the afternoon instead?) My PH has been holding steady at 7.6 for the last 10 days, but this morning it dropped to 6! I had read that this will stall the cycle so I panicked and did a 50% water change to bring my PH back up to 7.6.

For my fishless cycle, I've been using ACE Ammonia 10%. The only things in my tank are white gravel with a layer of plant substrate underneath it, Anubias Nana, Java Fern, moss and two other plants that I had gotten from another lfs store that I can't remember the name of, I'm sorry. I have 2 geode rocks that I got from that same store, a big hide from petsmart and a little hide from pet smart on the other side. It's heated to 84 degrees (to help with the cycle) and has a filter running with aeration.

Then I tested my water parameters again (after 30 min):

First AM read: Ammonia 2ppm, Nitrites 0.25ppm, PH 6
Second AM read: Ammonia 1ppm, Nitrites 0 (although it was SLIGHTLY purple, but not enough to be 0.25 ppm), and PH 7.6

So, scared that my Ammonia was so much lower, I dosed back up to 3ppm.

Did I totally screw up my cycle? Should I have waited?

 

Check your KH levels, low KH is often a cause of swinging pH. If they’re low, you may have to supplement your tank with crushed coral to stabilize your pH.

 

Ok thank you for the heads up! I just ordered the GH & KH test from Amazon and it will arrive tomorrow for me to check what my KH is.

 

Please be aware that the crushed coral isn't going to make quick changes to your KH/GH thus your PH readings but will stabilize it. I happened to have a bunch of seashells laying around and have been using them instead of crushed coral and they have worked well for me. Only you can determine exactly how much you are going to have to use for your tank but a good starting point is 1 cup. All you have to do to it is occasionally replenish it as it very slowly dissolves.

You can put the crushed coral in a bio bag and put it in your filter housing if there is room for it or you can just put it in your tank, preferably where there will be water movement over it. Some folks just scatter it in with their gravel.

 

Ok! So, depending on my KH test, crushed coral may be something that I have to continuously keep in my tank to help stabilize my PH levels for the life of my tank? Good to know! I would need to go to my lfs to get crushed coral some point soon then.

On a secondary note, did doing a PWC stall or ruin my cycle? Is it possible to bounce back from this little hiccup?

 

Ok! So, depending on my KH test, crushed coral may be something that I have to continuously keep in my tank to help stabilize my PH levels for the life of my tank? Good to know! I would need to go to my lfs to get crushed coral some point soon then.

On a secondary note, did doing a PWC stall or ruin my cycle? Is it possible to bounce back from this little hiccup?

Right. I have kept the shells in mine since I set it up over 2 years ago. I just add more as these dissolve. they dissolve very very slowly.

Unless you were using bottled bacteria that says not to do water changes then no, a water change isn't going to do anything but help your tank cycle. Just be sure to always use water treated with Prime or your water conditioner of choice.

The worst thing one can do is to ever let untreated water get in there. The chlorine will kill everything it touches. If you ever turn your filters off and have to prime them be sure to do it with either water from your tank or freshly treated water.

I only stress this because there was a lady that couldn't figure out why her tank wouldn't cycle. She finally realized that she was priming her filter with straight tap water.

 

I’m glad I read this thread! I had no idea ph swings during cycling were caused by low kh/gh. I experienced this during my fishless cycle, especially during the part where Nitrite started to appear, so I’d always assumed that was the cause. It’s good to know about the shells and such. I have low gh/kh. If it’s helpful at all the ph stabilized for me after the cycle was completed. I actually read that ph swings while the cycle is getting established is pretty normal, and as you said not to allow ph to get below 7. Or the ammonia and nitrites to rise above 4ppm as this could stall the cycle. But it also depends on what you used to start the cycle I think. Tetra Safestart in particular you just leave alone for 2 weeks and don’t even bother with checking parameters the first two days. No water changes until 2 weeks are up with that particular product. since your doing it fishless there’s no risk to fish of course during that period.

 

I'm not using TSS but instead I started with dosing with ammonia to bring it up to 4ppm and then waiting until it dropped to 1ppm before dosing again like the fishless cycle is outlined in the forum. But, it was the sudden drop of the PH to 6 that made me do my water change because I was scared it would stall. Hopefully, testing the KH will explain some things and I can stabilize so that the rest of it is as easy as the first part seemed to be!

 

First AM read: Ammonia 2ppm, 0.25ppm, PH 6
Second AM read: Ammonia 1ppm, Nitrites 0 (although it was SLIGHTLY purple, but not enough to be 0.25 ppm), and PH 7.6

I just re-read the part I quoted above. Was the second AM reading before or after the water change. If it was before and was 7.6 that would lead me to believe the first PH reading failed in some way.

Maybe didn't shake the bottle or mis-counted drops or something? For me I could blame it on not enough coffee

 

The second read was AFTER my water change if that helps! About 20 minutes or so. I'll probably do another test when I get home from work as well just because now I'm very nervous.

 

The second read was AFTER my water change if that helps! About 20 minutes or so. I'll probably do another test when I get home from work as well just because now I'm very nervous.

That makes sense. I have read that the PH can get lower during the night. Something about no light and photosynthesis or some such thing. It kinda went over my head but maybe it would be better to do the PH test later in the day to get a true reading.

I wouldn't think a 50% water change could have raised the PH from 6 all the way to 7.6 A swing that big can be very detrimental to your fish but if your fish aren't showing any signs of stress I am leaning toward a false PH reading and maybe it really never was that low.

 

Thank you! I usually test so early because I have a lot of free time in the morning, but I might also try to do it in the afternoon because I do turn off my lights at night. Luckily, I have no fish in there! I'm still in the 2nd week of my fishless cycling (about 10 days in to be exact) so no fishies to hurt, but I'm just nervous of stalling my cycle too much and extending it unnecessarily.

 

If you’re worried you’re changing the water too much I wouldn’t worry. But since you are fishless at the moment it’s worth noting that baking soda can be used to raise ph back to where you want it too. I had do this personally during my fishless cycle and it worked pretty well. After a few days the ph stabilized on its own as the nitrogen cycle completed and I didn’t have to mess with it. But of course every situation is different. I’m sure you’ll know more what to do next once you’re able to test your kh and gh.

 

Thank you! I usually test so early because I have a lot of free time in the morning, but I might also try to do it in the afternoon because I do turn off my lights at night. Luckily, I have no fish in there! I'm still in the 2nd week of my fishless cycling (about 10 days in to be exact) so no fishies to hurt, but I'm just nervous of stalling my cycle too much and extending it unnecessarily.

oops, I forgot that you were doing a fishless cycle and I can't even blame it on not enough coffee

 

Mine did that too. I had to start doing water changes. I settled on about 50% daily water changes after I'd probably spent two weeks with the cycle stalling due to high nitrites / nitrates and low PH. Once I started doing water changes to keep PH up and keep nitrites / nitrates from getting super crazy, the cycle finished up in a few days.

 

Word! With above. It sounds like you did exactly what was needed. I just chose the baking soda route because I was dosing the ammonia in a very specific way and it was just easier for me to add a teaspoon of baking soda. There’s lots of ways to do fishless cycling, and everyone’s tank is different. But I really don’t think what you did today will delay the cycle at all, it will definitely help move things along. And as said above it can help speed things up a bit.

 

I'm doing a fishless cycle as well and had a pH drop from 7 to 6. Temp 82. Dosing ammonia up to 2ppm. The only thing I have different from you is I'm dosing stability. Today I finally had a spike in nitrates to 40ppm, and ammonia is processing even with a low pH of around 6.3 (today's reading)

Edit: also I've only done one 30% wc to clear some tannins from leeching mopani(now removed)

 

UPDATE! Thank you to everyone who has helped so far! I really appreciate it.

I purchased the gh/kh test, and it took 4 drops to make the colors change for each test. If I'm reading the instructions right, this means my water is at 3°-6° (50-100 ppm) so most tropical fish including angelfish, cichlids, tetras, botia, live plants could live there?

Does this make sense with buffers and my PH dropping so suddenly? Or could I have made a mistake on my test?