Re-cycling tank

[KTpoopenstein]

So while my tank (aqueon 15 gal column with whisper 20 HOB filter) has been up and running happily for ~4 months, a batch of apparently sick platys from a LFS and the subsequent treatment ( API T.C. Tetracycline for fin and tail rot) appears to have knocked out my biological filter. Unfortunately, I didn't realize this until I had restocked. I currently have 1 sunset platy, 1 peppered cory, and 6 serpae tetras. I also have live plants including amazon swords (thriving), java fern, water wisteria, and scarlet temple.

I have been doing 20-50% water changes on an almost daily basis to keep the waste in check. After a ~50% change late last night when I got home from an overnight trip to find everyone looking a little iffy, the current parameters are:

Nitrate 5.0ppm
pH 6.4
Ammonia 0.25ppm
Nitrite 1.0ppm
Temp 76*F

For reference, my untreated tap water parameters are:
Nitrate 0ppm
pH 8.8+ (test kit tops out)
Ammonia 1.0ppm
Nitrite 0ppm

I treat with Kordon AmQuel and NovAqua and have been using Seachem Neutral Regulator to try to stabilize the pH. I have also been adding Top Fin bacterial supplement with water changes and API Leaf Zone ~weekly.

My pH has been all over the place. More often than not, it has been reading 6 (or lower-test kit bottoms out) even with the Neutral Regulator. Any suggestions? Everyone seems to be doing ok at this point - active and eating well (the serpae are voracious eaters!) but the daily WCs are getting a little tiresome!

 

[Rivercats]

Part of the reason your having trouble cycling is because of your Ph dropping below 6.5 which slows it down and ph under 6 stops cycling altogether. What I suggest doing is first add 1/8 teaspoon of baking soda (dissolved in water) to add buffer back into your tank. Then get some crushed coral and either put it in your filter or put it in a media bag and hang under your filter outflow. You start with a small amount of CC and add as needed. This is the best way to start and if it doesn't work there is something else that can be done. Also you may need to add 1/8 teaspoon of baking soda with each WC until your tank stabilizes.

 

[Rivercats]

Forgot to add you need to keep doing your WC's as often as needed to keep ammonia and nitrites down to .25 or lower.

 

[KTpoopenstein]

I did another water change this afternoon...about 4 gal.

pH 7.0
Ammonia 0.25ppm
Nitrite 0.25ppm
Nitrate 5ppm

I forgot to add that at the advice of the folks from Seachem, I've been using about double the amount of Neutral Regulator to help stabilize the pH where it should be and get it to where the buffer can do its job more easily.

{seachem's response to my inquiry} Thank you for your questions. Whenever the biological load in your aquarium increases, the acidity of your system can increase as a result. In addition, if your Alkalinity is low it will be more difficult to raise pH in a system. Therefore, your pH can not be maintained at a higher level until the amount of buffer in your system exceeds the amount of acid that is present. To remedy this, I would suggest that you increase the amount of Neutral Regulator that you are adding so that the buffer can overcome the acidity of the environment. If you want to speed up this process, you can perform water changes in addition to dosing Neutral Regulator to help increase pH and raise Alkalinity in your system.

I have at least been able to get the pH within the range of my test kit doing this. I'll give the NaHCO3 a try for now and if it remains an issue I'll look into crushed coral...I have the bicarb on hand, the coral will have to wait until I get paid again.

If anyone else has any further insight or tips I'd love to hear them! Thanks!

 

[Rivercats]

Remember Seachem is in the business of "selling" their products so of course they are going to recommend you use them... lol! You shouldn't have to add any ph/buffering product daily. Most ph product are a temporary fix and last only a day or so in solution.

 

[KTpoopenstein]

I went by my LFS who was out of crushed coral but had some small pieces of limestone base rock which they suggested instead when I said what I needed it for. It certainly looks better than a bag of crushed coral hanging in the tank and was a whole lot cheaper too since I could buy a 3/4 lb piece for $1.50 instead of a 20 lb bag of crushed coral! Hopefully things will stabilize now! Time will tell...

 

[KTpoopenstein]

So after I got the rock (but before I did anything with it) I did a water test and the results were:

pH ~7.0
Ammonia .25ppm
Nitrite 2.0ppm
Nitrate 20ppm

I did a 6gal water change (~40%) and added the rock (had to rearrange a few things and took out some java fern that was dying and cleaned up most of a lily that had died back) and tested the water again just now (~6 hrs later). Nitrate has spiked to 40-80ppm (seriously? Those are supposed to be different colors?) and nitrites are still high. I did not use the Neutral Regulator this time and just used AmQuel and NovAqua. Would the rock cause a spike in nitrate or nitrite? I usually see a significant difference with a much smaller WC and this has gone in the opposite direction. Pic of tests attached.

 

[KTpoopenstein]

Now I'm totally at a loss. I retested the water again this afternoon (first chance I've had today) and everything has zeroed out. No ammonia, nitrates or nitrites registering. I did a second test just to be sure and got the same results. pH has dropped again though so I'm still trying to get that to stabilize. Today's tests: