- Joined
- Dec 13, 2017
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I’m in desperate need of help because I’m completely at a loss as to why I can’t keep Chaeto alive.
I used to grow so much that I’d have to throw it out or sell 5-gallon buckets every other week. That system was eventually shut down, and my dad and I built a new setup. But ever since then, every time I add Chaeto to this system, it dies. I even swapped my Kessil fuge light for a Mars Hydro grow light, and my most recent batch is still dying.
We’re running a 375-gallon display and a 220-gallon display plumbed into a 150-gallon sump. The 375 had been running for about two years before we connected the 220.
I do have a QT system, so all fish go through quarantine. I avoided adding a cleanup crew for a long time, and the tank got pretty dirty. Nitrates and phosphates were very high, and when the fish got ich, I had to treat the display with copper. So, the tank didn’t get the care it needed for a while—but all my fish are now happy and healthy.
We’ve been doing 200-gallon water changes weekly for months now. Phosphate has come down to around 0.4 ppm, and nitrate is about 10 ppm. My last ICP test showed copper as undetectable.
I’m running a 120-watt UV and an MRC Pro-2 skimmer. I do have two large bashsea reactors I add carbon and gfo to also!
Because we’re changing so much water, we’ve been using Instant Ocean salt. My current parameters are:
I’ve attached my most recent ICP test as well. I really hope you can help me figure this out—I’ve put so much time and effort into this system, and I can’t understand why I can’t get Chaeto to grow. I’ve dosed pods and phyto, added batches of snails, hermits, and starfish, and even blow out the rocks before every other water change.
We’ve been keeping reef tanks for a long time and have had great success with corals, but this one has me stumped. Also my tank is not overrun with algae until recently I’ve finally had a cyano outbreak.

I used to grow so much that I’d have to throw it out or sell 5-gallon buckets every other week. That system was eventually shut down, and my dad and I built a new setup. But ever since then, every time I add Chaeto to this system, it dies. I even swapped my Kessil fuge light for a Mars Hydro grow light, and my most recent batch is still dying.
We’re running a 375-gallon display and a 220-gallon display plumbed into a 150-gallon sump. The 375 had been running for about two years before we connected the 220.
I do have a QT system, so all fish go through quarantine. I avoided adding a cleanup crew for a long time, and the tank got pretty dirty. Nitrates and phosphates were very high, and when the fish got ich, I had to treat the display with copper. So, the tank didn’t get the care it needed for a while—but all my fish are now happy and healthy.
We’ve been doing 200-gallon water changes weekly for months now. Phosphate has come down to around 0.4 ppm, and nitrate is about 10 ppm. My last ICP test showed copper as undetectable.
I’m running a 120-watt UV and an MRC Pro-2 skimmer. I do have two large bashsea reactors I add carbon and gfo to also!
Because we’re changing so much water, we’ve been using Instant Ocean salt. My current parameters are:
- Alkalinity: 8.4 dKH
- Calcium: 269 ppm
- Magnesium: 1130 ppm
- pH: 8.3 ( Apex probe might be bad)
- ORP: 184 (it’s been low for a while)
I’ve attached my most recent ICP test as well. I really hope you can help me figure this out—I’ve put so much time and effort into this system, and I can’t understand why I can’t get Chaeto to grow. I’ve dosed pods and phyto, added batches of snails, hermits, and starfish, and even blow out the rocks before every other water change.
We’ve been keeping reef tanks for a long time and have had great success with corals, but this one has me stumped. Also my tank is not overrun with algae until recently I’ve finally had a cyano outbreak.

Last edited:
Why 4000 GPH might be too much
Some members try to pass off AI replies as their own, which is a lot worse 

