Dosing EI mid cycle and nitrates dropped to 0?

[qoob]

Went on a work trip and instructed SO to dose EI daily.

Before trip ammonia was 0, nitrites 0.1 and nitrates 5 mg/l. Dosed EI according to instructions on the bottle - e.g. 1.5mg/l NO3 daily. After 5 days nitrates should've been cumulatively 5 + 5x1.5 = 12.5 mg/l minus whatever the plants consume. I also have Ada aquasoil (about 1 month old) and root tabs.

After 5 days the tank was full of diatom algae, even though had CO2 on. Lights were on 8 hours a day. I was mid cycle before the trip and now it seems the cycle has completed as Nitrites were close to 0.05. What is odd is that nitrates were close to 0 also. Other nutrients I could measure had increased compared to the values before my trip. Gh and kh seem to have increased by one degree also, oddly. I expected nitrates to increase, because of EI dosing and nitrites converting to nitrates. What's going on?

Increased co2 rate from the 1 bubble per second rate (120l tank, inline diffuser) to 1.3 bubbles per second, but did no other changes.

 

[ZxC]

What NO3 test are you using? API are notorious for false readings.
No kH should be present in a new aquasoil tank (the soil strips the water of all kH).
gH could be rising due to top-offs with tapwater and too little sized water changes.
Plants could possibly consume that much NO3, unlikely in a new tank though.
120L is ~ 30 gallons. You should be nearing 5 bubble per second to get up past 30ppm of CO2. (my 25 gallon ran at 4.75 bubbles per second into a 100% efficient inline reactor).
Algae is common in a new tank, 5-6 hours a day MAX in a new planted tank, especially with strong lighting.

Nice looking tank btw! It will look great once those plants fill in / colour up.

 

[qoob]

What NO3 test are you using? API are notorious for false readings.
No kH should be present in a new aquasoil tank (the soil strips the water of all kH).
gH could be rising due to top-offs with tapwater and too little sized water changes.
Plants could possibly consume that much NO3, unlikely in a new tank though.
120L is ~ 30 gallons. You should be nearing 5 bubble per second to get up past 30ppm of CO2. (my 25 gallon ran at 4.75 bubbles per second into a 100% efficient inline reactor).
Algae is common in a new tank, 5-6 hours a day MAX in a new planted tank, especially with strong lighting.

Nice looking tank btw! It will look great once those plants fill in / colour up.

I use a JBL brand water test kit. It has been kinda reliable based on my measurements before and after water changes. Kh hasn't been stripped away for some reason - it has settled around 2 which is what comes out of the tap. Gh is 3 out of the tap and rose to 4 during my absence. Kh also rose to 3. This is odd because there were no water changes and only ei ferts + flourish excel was added.

Tank is now on day 33 and I've done the following WCs: day 10 50%, day 16 50%, day 19 60%, day 21 60%, day 23 40%, day 25 20%, day 27 50% and now day 33 50%. So lately I've done quite a lot because I was trying to get rid of a detritus worm infestation (turns out WCs made it worse, unlike people say). Co2 was added on day 27 and I've done EI more or less according to instructions the whole way.

I've got a 20mg/l co2 drop checker that has been light green. Also got a more accurate test kit that I think measured 15mg/l before my trip. I'll definitely up the co2 rate then.

Thanks for the compliment! Can't wait to get the livestock settled. Currently I'm having a hard time keeping bucephalandra. They all seem to melt constantly. Everything else seems to be doing great.

 

[ZxC]

CO2 test kit? Never heard of a hobby grade one that would work. pH drop is much easier way to determine CO2.

Measure pH before any CO2 in in the water, then measure again after it's been on for a few hours, you'll see the pH drop. A god rule is to allow it to drop a full 1.0. That will get you close to 30ppm. No harm to livestock because no mineral content / osmotic pressure is changing, only the addition of carboxylic acids from dissolves CO2. (weak acid).

Drop checker set to 30ppm would be very light green, just about yellow at just over a 1.0 drop in pH.

 

[qoob]

CO2 test kit? Never heard of a hobby grade one that would work. pH drop is much easier way to determine CO2.

Measure pH before any CO2 in in the water, then measure again after it's been on for a few hours, you'll see the pH drop. A god rule is to allow it to drop a full 1.0. That will get you close to 30ppm. No harm to livestock because no mineral content / osmotic pressure is changing, only the addition of carboxylic acids from dissolves CO2. (weak acid).

Drop checker set to 30ppm would be very light green, just about yellow at just over a 1.0 drop in pH.

Yeah, one made by tetra. Works kinda like kh/gh tests where reagent is added to a solution drop by drop until water changes color.

My tap water pH is at around 7.5 but I've measured pHs of around 6.8-7.0 from the tank. I suspect the driftwood and aquasoil are dropping it. If co2 dropped it by one point I'd be at 5.8 - isn't that harmful to the bacteria in the filter?

I'll add the co2 rate slowly and work towards that drop. Also need to measure baseline pH before co2 again tomorrow.


Now that you're here - any ideas why my buces keep melting? And thank you a ton for all the help.

 

[ZxC]

Not sure why the buces are melting, how much Excel are you dosing? Could also be ammonia burn but I highly doubt it, especially after the aquasoil has finished leaching ammonia. Don't rely on those CO2 tests, they are ball-park at best.

That pH is fine, lots of aquasoil users are running those levels. I was running inert substrate and a degassed pH of 7.1 dropping it down to 5.9 without any issues in a fully stocked tank.

 

[qoob]

Not sure why the buces are melting, how much Excel are you dosing? Could also be ammonia burn but I highly doubt it, especially after the aquasoil has finished leaching ammonia. Don't rely on those CO2 tests, they are ball-park at best.

That pH is fine, lots of aquasoil users are running those levels. I was running inert substrate and a degassed pH of 7.1 dropping it down to 5.9 without any issues in a fully stocked tank.

Lately 2 capfuls a day to fight the diatoms. Was hoping to stop with the excel after I got co2 but perhaps I have to wait for the livestock and increase the co2 rate as per your suggestion. Ammonia has been 0 for 2 weeks, and some of the melted buce was added after that.

Good to know - getting some otocinclus cocama as part of the stocking and they are quite expensive. Wouldn't want anything bad to happen to them, and I've heard otos can be a bit sensitive.

 

[ZxC]

Yea otos can be, buy a two more than you think, the diatoms will vanish with 4-6 otos in there.

Keep trying with the buce, seems strange that they are melting on you like that, they aren't that finicky in my experience.

 

[qoob]

Yea otos can be, buy a two more than you think, the diatoms will vanish with 4-6 otos in there.

Keep trying with the buce, seems strange that they are melting on you like that, they aren't that finicky in my experience.

I upped the rate to 3 bubbles per second. Now the tank water looks like soda. pH has dropped to 6.2 (from 6.8). Kh is at 3 like yesterday. Did the co2 test and it showed a value of 50 mg/l. According to a CO2/KH/pH chart this pH would mean CO2 is at 56 mg/l. My 20mg/l drop checker however is yellow-green, bordering yellow.

What should I make of this? Probably need a reactor if I want to see my livestock. Any recommendations on that front? Does this sound normal at all to you, considering I have an inline diffuser? Thanks!

 

[ZxC]

I upped the rate to 3 bubbles per second. Now the tank water looks like soda. pH has dropped to 6.2 (from 6.8). Kh is at 3 like yesterday. Did the co2 test and it showed a value of 50 mg/l. According to a CO2/KH/pH chart this pH would mean CO2 is at 56 mg/l. My 20mg/l drop checker however is yellow-green, bordering yellow.

What should I make of this? Probably need a reactor if I want to see my livestock. Any recommendations on that front? Does this sound normal at all to you, considering I have an inline diffuser? Thanks!

Aquasoil tanks and pH drop can be funny. Your kH is certainly not 3 with fresh new aquasoil. That kH/pH/CO2 chart is outdated, don't rely on it.

Also, pH liquid tests are not accurate either...

Are you using tap water? What's its kH?

 

[qoob]

Yeah, tap water. Its kh is around 1.5, just measured to be safe. Tank kh is at 2.25ish instead.

pH kit results are quite consistent with the results I've heard from other local hobbyists and results from the water treatment plant. pH should be around 7.5 out of the tap, but in my tank it is clearly under 7, since that's where the kit turns from blue to green.

 

[ZxC]

Yeah, tap water. Its kh is around 1.5, just measured to be safe. Tank kh is at 2.25ish instead.

pH kit results are quite consistent with the results I've heard from other local hobbyists and results from the water treatment plant. pH should be around 7.5 out of the tap, but in my tank it is clearly under 7, since that's where the kit turns from blue to green.

Well yea, in the tank the pH should be like 6.4 from the aquasoil buffering it down.

1.5 from the tap is fine, the aquasoil will eat that up without any issue.

Which test kit are you using?

 

[qoob]

Well yea, in the tank the pH should be like 6.4 from the aquasoil buffering it down.

1.5 from the tap is fine, the aquasoil will eat that up without any issue.

Which test kit are you using?

I've had pH at around 6.8-7 in the tank since the start of the tank. It has dropped to 6.2 only after injecting co2.

Kh has been around 2 for the whole time with the exception of buffering it for a short while at the start when I didn't know better.

Here's a picture of water param progression https://imgur.com/gallery/hifxert

All my water test kits (except co2) are JBL brand.