Resource Experience with APT Feast

[Sb1415]

Setting up a new tank with APT Feast aquasoil and thought it would be useful to share my experience as a resource since it is relatively new and lot of people have shown interest in it.

Tank - 25 gallon - Waterbox mini 25 (60 cm x 40 cm x 40 cm)
Aquasoil - APT Feast - 2.5 packets - ~12 liters - bought 3 packets (15 liters) online via Amazon for 75$ - came with a small bottle of APT pure as well.




Hopefully this gives you a good idea of the grain size.

Cycling:
Doing a Dark Start
Filter:
- Oase biomaster 350 (pre-cycled filter media from an established aquarium - seachem matrix and Sponges)
Day 1:

• Turned on Filter
• Squeezed in Mulm from old Filter sponge as well
• No Co2/Light
• RO Water - (No added minerals or fertilizer under the recommendation of the 2Hr Aquarist team)
• Enclosed the aquarium from ambient light as well to be safe.

Day 2:
- Ammonia - 8.0 PPM (Using API master test kit, this is the max ammonia reading)
Day 3:

• Ammonia - 8.0 PPM
• Nitrate - 0 PPM (Using API master test kit)
• Performed 90% water change with RO water

Day 4:
- Ammonia - 8.0 PPM
Day 5:

• Ammonia - 8.0 PPM
• Nitrite - 0 PPM
• Nitrate - 0 PPM
• Squeezed in more mulm from filter sponge of a different aquarium.

Will post more updates soon. Will switch to a new journal once i start planting.

So far, my main take away is that if I had planted this without dark start and just with a pre-cylced media, I might have had good amount of melt off. Dennis had posted on quick cycling with APT feast (i.e, plant heavily the second day after 100% water change) but did not want to take a chance.

 

[techman81]

Interesting that Dennis mentions doing a big water change during dark start. Everything I've read says not to. I didn't do a water change on my first tank which went through a 1 month dark start.

 

[Sb1415]

Interesting that Dennis mentions doing a big water change during dark start. Everything I've read says not to. I didn't do a water change on my first tank which went through a 1 month dark start.

I don’t think he does, he mentions water change when wanting to go through it quickly (i.e when wanting long to plant immediately) - . I just did the water change since I wanted to see if it would help the cycle since the ammonia load was so high.
Based on my understanding I don’t think the water change affects the dark start in any negative way.

I think it is just convenient not to do any water change. If incorrect, someone please comment.

I should probably just leave it alone…. But then where is the fun in that!

 

[BenB]

Setting up a new tank with APT Feast aquasoil and thought it would be useful to share my experience as a resource since it is relatively new and lot of people have shown interest in it.

So far, my main take away is that if I had planted this without dark start and just with a pre-cylced media, I might have had good amount of melt off. Dennis had posted on quick cycling with APT feast (i.e, plant heavily the second day after 100% water change) but did not want to take a chance.

This is great. I plan on using it the next time I rebuild my tank. It would be great to have a documented first hand experience from someone.

 

[techman81]

This is great. I plan on using it the next time I rebuild my tank. It would be great to have a documented first hand experience from someone.

I'm using it in my new 25G scape as well, so we'll have lots of info to compare.

 

[BenB]

I'm using it in my new 25G scape as well, so we'll have lots of info to compare.

I didn't remember that, but I'm subscribed to your journal. So I'll keep an eye out for those.

 

[techman81]

I didn't remember that, but I'm subscribed to your journal. So I'll keep an eye out for those.

I haven't started the journal on this one yet. Soon, but still deciding style. Just shifted from triangular nature style to Brazilian style using dragon stone. Will experiment with some layouts tomorrow.

 

[BenB]

I haven't started the journal on this one yet. Soon, but still deciding style. Just shifted from triangular nature style to Brazilian style using dragon stone. Will experiment with some layouts tomorrow.

Ha, I thought I followed you somewhere. Maybe it's just that we chase each other around some of the same threads a lot here.

 

[techman81]

Well, I do have journals on my first 3 tanks now, including one I just started yesterday on my nano tank.

 

[Sb1415]

Interesting that Dennis mentions doing a big water change during dark start. Everything I've read says not to. I didn't do a water change on my first tank which went through a 1 month dark start.

Actually I stand corrected, I think on his website he does recommend changing the water Should I bother cycling a planted tank before planting? Introducing the dark start.
Again not sure how important it is.

 

[Sb1415]

Thought people would find Chat GPT's response to my question on this interesting -

My Question " I am trying to cycle my tank with aquasoil, but i am using a pre-cycled filter and have squeezed in mulm multiple times but my tank is not cycled after 1 week with dark start. What is the reason ? there is plenty of ammonia, and I have added lot of bacteria why doesnt it start soon. "

ChatGPT said:​

This is a great question — and one where wearing both the aquascaper’s hat and the freshwater microbiologist’s hat helps make sense of what’s happening. Let’s break it down:

---

1.​

• Aquasoil (ADA, Tropica, UNS, etc.) leaches a LOT of ammonia in the first 2–4 weeks.
• That creates the impression of “plenty of food” for bacteria, but the concentration is usually toxic (>4–5 ppm).
• At high levels, Nitrosomonas (ammonia oxidizers) and Nitrospira/Nitrobacter (nitrite oxidizers) are inhibited or even killed off.
• So instead of “feeding them,” you’re overwhelming them — the bacteria you added from the pre-cycled filter and mulm can’t expand until ammonia drops into a friendlier range.

---

2.​

• Mulm squeeze introduces a broad microbial slurry (mostly heterotrophs, detritus decomposers, some nitrifiers). But nitrifiers are a minority in mulm and grow slowly.
• Your pre-cycled filter may have had an established community, but when transplanted to a brand-new, ammonia-saturated aquasoil environment, those bacteria face:
  
  • Osmotic stress (different water chemistry, KH/GH shifts).
  • Nutrient shock (sudden ammonia spike).
  • Competition from heterotrophs, which bloom first and can outcompete nitrifiers for oxygen and surface area.
• Result: the seeded bacteria don’t die completely, but they’re suppressed and can’t establish as fast as you expect.

---

3.​

• In a dark start (no plants, no light):
  
  • You avoid algae blooms, which is good.
  • But you also miss out on plants helping uptake ammonia/nitrite — so all the nitrogen load rests solely on microbes.
  • The microbial succession takes longer because there’s no “safety net” from fast-growing stem plants.

---

4.​

• Ammonia-oxidizing bacteria (AOB) have a doubling time of ~12–24 hours under ideal conditions.
• Nitrite-oxidizing bacteria (NOB) are even slower.
• In aquasoil tanks, the initial NH₃ > 5 ppm stalls both AOB and NOB growth, no matter how much you seed.
• Heterotrophic bacteria from mulm explode in numbers first, creating a biofilm and consuming oxygen, which further slows nitrifier colonization.

---

5.​

• Water change strategy: Do large, frequent changes (50–80%) to dilute ammonia from aquasoil down to ~2 ppm. This puts it in the “sweet spot” for nitrifiers.
• Aeration: Strong surface agitation helps — nitrifiers are oxygen-hungry.
• Patience with bacteria: Even with seeding, expect 3–4 weeks minimum for aquasoil tanks. They don’t behave like bare-bottom sponge-filter shrimp tanks.
• Plants as allies: Once you finish the dark start, adding plants will instantly stabilize ammonia swings and give nitrifiers breathing room.

---

Summary:
Your tank hasn’t “cycled” yet because excess ammonia from aquasoil is stalling nitrifier growth. Mulm + pre-cycled media help, but nitrifiers need time to adapt, and heterotrophs bloom first in new aquasoil environments. The key is to dilute ammonia to <2 ppm and keep oxygen high so the nitrifiers you seeded can actually expand.

 

[Sb1415]

So updates

Day 6
All test via API

• ammonia 8 ppm
• nitrite 0
• nitrate 0

95% water change

Day 7

• ammonia 6-8 ppm
• nitrite 0
• nitrate 0

90% water change
Recheck in 10 hrs

• ammonia 2 ppm
• nitrite 0
• nitrate 0 (by API)

Had a hard time telling whether there were nitrates or not so repeated it with Salifert
- nitrate ~ 0.5- 1 ppm


Hopefully with the reduced ammonia, there should be more nitrate conversion occurring. Looks like with my prior mulm and the pre-cycled filter there are already nitrate conversion occurring, but just at a retarded phase due to the high ammonia. Will see how things progress this week!!

 

[techman81]

Cycling just takes time. Now that your ammonia is dropping though, you can try this. I can't say with much certainty that it really does much, but I used it cycling my farm tank and it did seem to go a little quicker.

 

[Sb1415]

Cycling just takes time. Now that your ammonia is dropping though, you can try this. I can't say with much certainty that it really does much, but I used it cycling my farm tank and it did seem to go a little quicker.
View attachment 10357

Thanks I just keep squeezing some filters from my other aquarium, assuming it will have the same as the bottled ones. Do you use this even when you have cycled media available?

 

[techman81]

Thanks I just keep squeezing some filters from my other aquarium, assuming it will have the same as the bottled ones. Do you use this even when you have cycled media available?

I didn't really have much cycled media to share between the 3 tanks I currently have running. I think I did squeeze a sponge from the first tank into the 2nd nano tank and swapped one tray of Matrix from the Biomaster 600 to the 350 of the farm tank. Also, I wasn't in a big rush. I was just curious if the "One and Only" did much. I will be swapping a couple trays from the 600 to the 250 that I'll be using on the new 25 gallon.

 

[Asher E.]

Setting up a new tank with APT Feast aquasoil and thought it would be useful to share my experience as a resource since it is relatively new and lot of people have shown interest in it.

Tank - 25 gallon - Waterbox mini 25 (60 cm x 40 cm x 40 cm)
Aquasoil - APT Feast - 2.5 packets - ~12 liters - bought 3 packets (15 liters) online via Amazon for 75$ - came with a small bottle of APT pure as well.


View attachment 10209

Hopefully this gives you a good idea of the grain size.

Cycling:
Doing a Dark Start
Filter:
- Oase biomaster 350 (pre-cycled filter media from an established aquarium - seachem matrix and Sponges)
Day 1:

• Turned on Filter
• Squeezed in Mulm from old Filter sponge as well
• No Co2/Light
• RO Water - (No added minerals or fertilizer under the recommendation of the 2Hr Aquarist team)
• Enclosed the aquarium from ambient light as well to be safe.

Day 2:
- Ammonia - 8.0 PPM (Using API master test kit, this is the max ammonia reading)
Day 3:

• Ammonia - 8.0 PPM
• Nitrate - 0 PPM (Using API master test kit)
• Performed 90% water change with RO water

Day 4:
- Ammonia - 8.0 PPM
Day 5:

• Ammonia - 8.0 PPM
• Nitrite - 0 PPM
• Nitrate - 0 PPM
• Squeezed in more mulm from filter sponge of a different aquarium.

Will post more updates soon. Will switch to a new journal once i start planting.

So far, my main take away is that if I had planted this without dark start and just with a pre-cylced media, I might have had good amount of melt off. Dennis had posted on quick cycling with APT feast (i.e, plant heavily the second day after 100% water change) but did not want to take a chance.

I found a way to test ammonia past 8ppm with the api test kit.
i took 1ml of the water I was testing from my tank with apt feast, and I took 4ml of RO water. So that way the ammonia was diluted to 1/5. So I tested it and it read 4ppm, but that was 1/5, so just x5 it and I got 20ppm of ammonia.

 

[Sb1415]

I found a way to test ammonia past 8ppm with the api test kit.
i took 1ml of the water I was testing from my tank with apt feast, and I took 4ml of RO water. So that way the ammonia was diluted to 1/5. So I tested it and it read 4ppm, but that was 1/5, so just x5 it and I got 20ppm of ammonia.

Super nice Hack! trying it later today!

 

[techman81]

Any updates on the cycle?

 

[snowballs99]

i also bought a bag of 5liter apt feast to try out.

3 days so far in a 10 gallon tank, layered under 1 inch of old aquasoil (I basically replaced the soil in the current tank).

I have an ammonia test kit arriving today so I should be able to take some readings as well.

 

[Asher E.]

i also bought a bag of 5liter apt feast to try out.

3 days so far in a 10 gallon tank, layered under 1 inch of old aquasoil (I basically replaced the soil in the current tank).

I have an ammonia test kit arriving today so I should be able to take some readings as well.

If the ammonia tests off the chart you can dilute it. Use 1ml of tank water and 4ml of water without ammonia, instead of 5ml of tank water. And then whatever the result is just multiply it by five.
Mine was about 20ppm of ammonia from apt feast.