Fishless Cycling Help - Nitrate Fluctuations & Other Qs

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SeemsFishy

Aquarium Advice Apprentice
Joined
Apr 12, 2020
Messages
10
Location
Philadelphia
Longtime lurker, first time post. Thanks all for contributing to these threads, which have been hugely useful and informative.

I've gotten to a point in the cycle where things are changing quickly, but some unexpected developments have cropped up. Looking for help on these specific issues, and also any tips for getting from here to ready to stock. My end goal is a healthy tank with enough vegetation to satisfy a couple of aquatic dwarf frogs, a few danios, and a couple of mollys. Thank you!

Current Issues:
  • NitrAtes are fluctuating between 80/160+ (yes, I did bang, shake, and otherwise abuse bottle #2), and shot back up after a 50% change. Do I WC again?
  • Filter is disgusting (gross to me, good for cycling, I know) and may have some mold on the back --> when can I replace the filter, should I clean or rinse it off in the meantime
    Filter.JPG
  • Replacement heater recommendations for 20gal tank
  • Nitrites and Ammonia still haven't hit 0, though ammonia is bottoming out at .25 consistently (I assume it's still cycling and they will eventually, unless I'm missing something)
  • When should water changes be done? (Only change so far is 50% when nitrates stayed at 180+)

Tank Equipment: 20gal hex tank, Top Fin Silenstream 20 Power Filter w/ Large Cartridge, heater malfunctioned during cycling and not replaced yet. There is a large piece of fake coral in the center topped with dead coral on top of a white gravel substrate.

Tank.JPG

Inhabitants: 1 morimo ball, 1 ozelot sword plant, 3 java ferns. All were planted at tank set up, directly into the gravel substrate. Morimo was removed when the heat was cranked up but was put back a couple of days ago.

I also planted an Anubius when I set up the tank. It stayed stable for a couple weeks, but went downhill after I turned up the heat. Leaves developed brown then translucent patches until it was half pitiful and half green. I left it in until I did the tank change as an ammonia source.

Cycling Method & Progress: Fishless cycling.

At the beginning I put a "weekender" feeder block and about a teaspoon of fish flakes into the aquarium. I agitated the water daily to break up the flakes/feeder block by using a pitcher to scoop tank water out pour it around the edges. I did not add any new food after this.

After about a week, I turned up the heat to 85-90 F. After about two weeks at high heat, I found that the heater was malfunctioning (overheated, melted all the rubber around the end of it). I removed the heater and water has been a steady room temperature of 71 F for the past 2-3 weeks.

Ammonia increased as soon as the temperature increased,
Once the nitrites kicked off, and the ammonia levels plummeted, I started adding 1.5-2 ml household ammonia if daily readings were down to .25 ammonia.

Testing & Levels: Using an API freshwater kit for daily testing, along with some basic strips to test hardness. The charts below are from daily testing.

My Nitrates were consistently at 120 then started fluctuating between 160, 80, 40. Once they went back up to 160+ I decided to do a water change of 50% to also remove the gnarly fish flakes still floating around, and rinse the algae off the coral.

WC: I removed the coral piece and put it in the bathtub, then used a soft brush to lightly loosen to worst areas of algae (not the whole or even most of the piece). I used a pitcher to agitate the water, scoop up a pitcher full of water with flakes, then poured it on any dense algae spots on the coral. I did this until there were no capturable flakes in the tank, which was about 50%. Refilled with same temp water conditioned (tap has chlorine & chloramine).
Immediately pre-change: Ammonia 0.25; Nitrites 2; Nitrates 160
Immediately post-change: Ammonia .75; Nitrites 5; Nitrates 40
-->Then added 1.5ml ammonia
Day after change (yesterday): Ammonia .25; Nitrites 2; Nitrates 160
Today: Ammonia .25; Nitrates 2; Nitrates 80

Hardness readings weekly have stayed @ KH 40; GH 180.

Charts.jpg
AqTimeline.JPG
 
Last edited:
for starters, neither Anubias or Java Fern are stem plants. They feed off water column, if you plant the rhizome they will die.
 
And your numbers don't make any logical sense at all. Your Nitrates can't logically go from 40-160 overnight, that doesn't make any sense. What is your water coming from and what does it test before you add it to the tank?
 
A friend of mine got a 2nd hand tank and they was a getting overnight increases of 100ppm of nitrates. They nailed it down to a decoration leeching nitrates into the water. Something to consider regarding your own high nitates.
 
Thanks all.

The plants have been growing new leaves, so I would never have realized. Can I uproot and just tie to a suction and suction them to the bottom, but leave rhizomes exposed on top the gravel? Otherwise they float.

And the nitrate fluctuations were my biggest concern.
Tap is my water source (conditioned of course) and reads:
7.2 ph
Ammonia: 1 ppm
Nitrites: 0 ppm
Nitrates: 5 ppm

Tank water readings:
Yesterday: A = .25; NI = 5; NA = 160 (after readings, added 2ml ammonia)
Today: A = .25 ; NI = 5 ; NA = 160
 
you can tie the anubias down with thread, fishing line, or glue it to a rock or piece of driftwood.
 
Resist the urge to clean that filter! What kind is it? Is there any separate biological media or room to add any?

The cycle looks normal just incomplete. The nitrate test can be finicky so I would bet some of your variation there could be due to that. Plants and algae could also be intermittently using up nitrates though it doesn’t look like you have too many yet.

Without inhabitants you really don’t need to worry about water changes until the end.
 
Thanks, y'all, I will take care of my poor plants then keep calm and cycle on. :)

The algae is starting to really bloom now, though. That'll be fun later, probably futile to deal with anytime soon :-(

Libertybelle, its the top fin hang on filter that came with the tank. There's the blue plastic bio piece, but the actual filter is some kind of prepackaged unit and I don't see a space for other media.
 
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