Backyard Aquaponics
A place to discuss aquaponics

I thought my cycle was established okay but I’m still a victim of past/present substandard decision making.

Setup:
150 gallon flood and drain, clay media system. Red compost worms added to grow bed yesterday
23 bluegill (2 died in past 7 days)
pH 7.8
NH3 0.25
‘trites 40?
‘trates 100+ (2 days ago).

I have to dilute the sample to get a measurable ‘trites level. Hard to trend that way. Last two samples I diluted 19:1 filtered:system water. First measurements:
Morning 1ppm
Afternoon: 2ppm. (20 and 40 ppm after accounting for dilution). So appears to be trending up, but huge margin for error in those measurements. Also fed them a lot 48 hours ago and a little after the morning measurement.

I have a couple decisions to make:
Feed or fast?
Water change or no water change?

I’ve fed them 3 times in seven days since I got them. Twice to their fill and once just a little. I don’t want to starve them, but feeding won’t help get ‘trites down.

Do water changes hurt the bacteria colony? Would I be setting myself back if I do another one? I did a big one three days ago and don’t want to over stress the bacteria or the fish.

Fish seem happy. They most chill at the bottom, but right now they are 6 inches below surface. They eat heartily. A couple attacked the syringe I was using to draw sample water and all came to see if I had food.

Water change?
Fast or feed?

I think water changes and no feeding until cycle is complete is the way to go. Water must be chlorine-free, ie, allowed to sit for chlorine to dissipate. If the fish struggle, salting the system will hep them deal with the nitrite levels. Search for recommended levels of salt... I seem to remember 4-6ppt or so, there again the limits will depend on the tolerance of your fish species.

Had the cycling process finished before you added the fish, ie: You achieved a certain Ammonia level, which started dropping after a few weeks, followed by a Nitrite spike, and both Ammonia and Nitrite then dropped to 0.0ppm?

What is the total wet gravel volume in the GB's?... Remember not to include the top 2" dry layer in your calc's.

My recommendation, before you go doing any more water changes etc, would be to check that your test kits are in date and that you are following the testing procedure to the letter. It is extremely unlikely that you'd have a Nitrite level of 20ppm, never mind 40ppm, for two reasons:

(1). During cycling, the Nitrite level usually ends up around 2x, or maybe a little more, than what your maximum Ammonia reading was, which would suggest a minimum Ammonia level of at least 10ppm. At that level the cycling process would've stopped and not progressed any further.

(2). Even at 20ppm, never mind 40ppm, it would be very unlikely that your fish would survive, let alone be looking for a feed. Even at levels down around 3 or 4ppm you'd probably see them not eating, lethargic, and all crowding around any aeration source in the FT.

If after checking the use-by on your kits and following the testing procedures correctly you still get the same readings, I would try finding an aquarium store etc that will test a water sample for you.

At the time I added the fish, NH3 was 0. I believed ‘trites were 1 or 2 ppm, but now I think they were very, very high (over 100)
When cycling I added way too much NH3 and had to perform several 90% water changes to get it down. When I went back and did the math on what I did, I figure I probably had NH3 north of 800ppm. (stupid just comes naturally to me)

Earlier this week I got frustrated with the API ‘trites test. It appeared low, but the color didn’t really match anything on the scale. That’s when I took a sample to the aquarium. They just used a test strip, but it immediately went off the chart high. I immediately did two water changes to bring down and lost two fish in the process.

I have verified the current readings with API and Sera test kits, and a test strip. I’m about to take my morning readings and let you know what I find.

Volume of growbed is 200 gallons. At high water mark 120 gallons.

Morning tests confirmed 20-50 ppm nitrites. I feel around the 25-30, assuming Sera is the most accurate.

I have a friend with a rainwater barrel. I'll probably do a small water change this morning of 20%

I'm extremely frustrated. 'trites seemed to be slowly trending down. And then this morning, I get 40 by the Sera kit, and over 100 by the API!

I didn't feed the fish at all. Where could this nitrite spike come from?

I feel like putting my head through a wall. I am so frustrated.

My plants are looking horrible. Of course they're looking horrible. I haven't been feeding the fish, so they have no nutrients.

I have no idea what to do other than infinite water changes.

Everything is going to die soon because of me

Fish can go for long periods without food (not just days but weeks - really young fish aren't quite this durable). The main issue is if they did suffer nitrite poisoning then often there is unseen damage that kills them off over several weeks.

If your nitrites jumped something is still being converted to nitrites. If there is no detectable ammonia and you haven't added any ammonia, then some other precursor could be breaking down (like a dead fish or other organic matter) to ammonia which rapidly winds up as nitrite since the system is apparently only cycled this far.

When you do water changes try to use dechlorinated water.

Is your water source water chlorinated or chloraminated?

Municipal water has chloramines. I use a combination of RO and filtered. The filter is supposedly 99% effective at removing chloramines, but latest water change I used a small amount of dechlorinator (20% the recommended dose)

I ended up doing a big water change today, then fed the fish. They are 2" bluegill. I inspect for dead ones every 12 hours.

Undiluted sample measured 2 ppm 'trites on the Sera. 19:1 solution measured .5 ppm on the API, so 10 ppm.

I've been using Nite Out II, but the aquarium store guy recommended Seachem Stability. I searched the forums here and saw other members recommended it so I put in a half dose as well.

I will fast them for 72 hours or when 'trites are 0, whichever comes first.

I am expecting they will all die soon

Blood pressure starting to return to normal.

Sera showed nitrites increasing from 2 to >=5, but API held steady at 10. 19:1 dilution of Sera showed 0ppm, so it's also reading somewhere around 5-10ish.

Fish seem happy. Came to ask for food while I was retrieving samples. I declined to feed them. Inspection revealed no dead fish and NH3 has been reading a steady 0.25 (maybe 0?).

Bluegill are pretty durable as fish species go so who knows . If you salted the water that helps prevent nitrite poisoning - the chloride ion competes with the nitrite ion (use uniodized salt that doesn't have anti-caking agents added). You can usually find it in bulk or as pool salt (NaCl is what I'm talking about but CaCl2 will also work but at a different amount) The level I recommend is 1 part per thousand (strawberry plants won't do well with this but most other plants should be OK). The salt also helps the fish with stress and helps them build a slime coat.

Usually if they've been seriously injured by the nitrite poisoning they'll die one or two at a time over a period of weeks. It usually helps to increase the aeration because much of the damage is to the gills.

Thanks Scotty. Having someone to talk it through with helps a lot.

Doing back calculations from current levels and previous water changes, I think I got nitrites well over 100. Ugh. Stupidity at it's finest. I'm expecting the worst and hopefully the fish will surprise me.



Red 'trites measurement in the pic is my best guess, derived from the measurements I took on the far right from different test kits at different dilutions. Lotta variation but trend seems up. If it doesn't reverse by tomorrow I'll do another 50% water change, unless someone recommends against it.

Sending up the bat signal to @scotty435 @mr damage @danny



No real trend at all. Seemed to be drifting up and now seems to be drifting down. The X20 API test is taking longer to develop from a 0 baby blue color, and the x10 Sera seems to be getting closer to a zero reading, but I still called it 0.5 (or 5ppm once accounting for dilution.

So seems right direction, but I feel there's a lot of room for error with dilution and choosing the closest color, so low signal to noise too.

Fish continue to fast. Last water change 48 hours ago. Last feeding 48 hours ago?

Water change or no?

It's a toss up - I could go either way myself on doing the water change (because I'm not convinced that the readings we're getting are true), I'll leave that choice up to you. For now, test the water you use to do top ups/water changes. Take some of the top up source water and divide it into two portions. Treat one portion with whatever you're using for dechlorination and leave the other portion untreated. Test each portion for nitrites at the beginning and again after sitting in the open for 24 hours. You're looking to see where some of these nitrites are coming from - sometimes it's the top up water and sometimes it's interference from the chemicals used to treat the water - or it can be neither of these .