Fishless Cycling Stalled And Don't Know Why!

[JALouis]

I can't thank you all enough for all your advice. Hopefully chaning the water will kick start it again.

Thanks again,
Jennifer

 

[JALouis]

Hi,

I tested the ph level again tonight and it looks like it's dropped a little already (it's been about 24 hours). It's down to somewhere between 6.8 and 6.6. What should I do? Should I continue to do large water changes (or small ones everyday) or is there something else I can do? I'm going to keep checking it each day. Hopefully it will stay at this level and not continue to go down.

Thanks,
Jennifer

 

[waterdrop]

Jennifer,

I would do another large water change and get the pH back up that way again. We want to resist for a bit the baking soda route, although we may end up going that way if this keeps up. Its just that the very thing of having the pH pushed down by the cycle does indicate fairly good progress from the cycle itself and a few big water changes might see you through without us having to get that salt in there. Make the change large and don't forget to recharge with ammonia.

~~waterdrop~~

 

[JALouis]

Thanks Waterdrop. I was busy all day today so I didn't get to the water but when I checked the ph tonight it was down to 6 again but the ammonia dropped below one as well. This is the quickest it's dropped so far. It's been about 48 hours. I will do another large water change and hope this helps. I'm happy to hear that this means the cycling is progressing. I will keep doing the water changes and keep you updated.

Thank you again,
Jennifer

 

[drobbyb]

With a drop that fast, I'd go out on a limb and say that you probably have a low KH. Common baking soda will correct this and raise your pH back up. I would also recommend that you purchase a KH test kit, and let us know the results.

For your tank, adding 4 and 1/4 teaspoons baking soda will raise your KH 4 degrees german. This should put your pH up a bit, probably close to neutral.

 

[JALouis]

Thanks. I do know that I have soft water. That might explain the ph crash. I did a 90% water change again yesterday and the PH was a little above 7 last night. This morning I checked and it had dropped a little but no where near as fast as last time. If it starts to get to low or continues to drop, I will try the baking soda to get it back up. At least since it a fishless cycle I won't harm any fish.

Thanks,
Jennifer

 

[waterdrop]

Sounds good and I agree with Robby, I'd be using this time to look around for a KH kit or a KH/GH kit that's liquid based. They are pretty rare to find at the LFS unless you happen to be near one of the rare real hobbyist stores that still exist. Otherwise its usually something you have to get off the net. I don't believe these tests are particularly tricky to make and so any brand should do. TetraTest makes a KH one that's been fine for me. API makes one with both GH and KH which is fine.

Having the KH one (which will measure your total alkalinity) will give you a tool that warns you ahead of time that a pH crash may be coming up sooner rather than later. These kits are also nice for having "nice to know" measurements for the longer term as you continue to learn about fish and plants in aquariums. Personally, I find it kind of amazing how you can keep adjusting your image of this kind of information over and over again as time goes by.

~~waterdrop~~

 

[JALouis]

Thanks Waterdrop. I'm hoping when I test this evening that the ph hasn't dropped too much. I found the API test kit on line so I will definitely get one of those.

Thanks again for your help and cross your fingers I can get the tank cycled (eventually).

Jennifer

 

[JALouis]

Should I consider putting some crushed coral under the gravel to keep the ph steady. I do remember in my last tank I had a couple of fish die because of a ph problem. Would I be better off with the crushed coral then trying to add baking soda? How much crushed coral would I need to use. Would I just put it under the gravel already in the tank?

Jennifer

 

[drobbyb]

That's a big question. I run crushed coral because of my KH, but there is a catch: If you go too long between waterchanges, you will subject your fish to pH shock. Crushed coral can be a great tool, but it can also be a bad thing.

In your case however, I think you would be fine with a bag of it in your filter. I can't tell you how long between waterchanges you could go, but regular testing will tell you. We aren't aiming to increase your pH or KH, rather we are preventing a pH crash. For me, I must do a weekly waterchange of at least 50%.

 

[waterdrop]

Jennifer, my own feeling is that its pretty clear-cut that once you have fish then crushed coral is the only way to go, if you're going to do it. (Which is a big if, as you can tell from Robby's comment. Crushed coral in a mesh bag in the filter is nice and slow, which is what you need with fish in the tank. Baking soda is usually too fast, unless you had extreme patience and were sitting at the tank all the time with your little teaspoon or something crazy like that.

On the other hand, during fishless cycling baking soda is preferred, precisely because of its greater speed and flexibility. Since there are no fish in there to worry about and the bacteria are not bothered by quick changes, we might as well make nice big fast changes to accomplish our goals.

My own personal situation is a lot like Robby's situation. I have extremely soft water KH=0 or KH=1 or something like that and my tap pH is not exceptionally high, something like 7.2 to 7.6 at different times. My tank works its way down from 7.2 to 6.6 or 6.4 in fairly short order and then gets a lift back up to 7.2 or more when I do the weekly 50% water change. I have a bag of crushed coral in storage and ready to go but still can't make myself decide whether to make this change and put it in my filter. I keep wanting to inventory all my plants and fish and think about how it would affect them. My gut feeling is that very soft acid water is really only useful if you want to breed a few species that reallly like it, and in all other cases (most plants, most fish) its really easier not to have it so soft and acid. But I have occasions when I can't manage to do the weekly water change and for the reasons Robby mentions, that worries me. I only mention this as an example about the thinking, but also, for me, its been bothering me for a year or so!

~~waterdrop~~

 

[JALouis]

Thanks Waterdrop. That makes perfect sense. The ammonia is now dropping to 1ppm from 4ppm in about 36 hours. Hopefully this will continue and the tank will start cycling again.

Thanks,
Jennifer

 

[JALouis]

Hi. I wanted to give you all an update and to ask for some more advise and/or opinions. Once I started keeping the pH level from crashing using baking soda, the cycle started right back up. The ammonia now drops to 0 in about 12 hours. However there are no nitrites. Could I have missed the nitrites spike before the pH started crashing? I tested for nitrates and they are now at 5. I thought the nitrates should by very high. Does it take time for the nitrites to show up after the ammonia starts dropping so quickly?

Thanks

 

[OldMan47]

The nitrites show up as the ammonia is being processed. It results from converting the ammonia. Each 1 ppm of ammonia that gets converted should produce about 3 ppm of nitrates. Unless you are doing large water changes, the nitrates should be climbing sharply. The other thing that might explain your chemistry results is if you have lots of growing plants in the tank.

 

[JALouis]

There's nothing in the tank. I definitely don't have nitrites but the ammonia is being process from about 4ppm to 0ppm in 12 hours.