Need some suggestions on how to bring up my Phosphate and Nitrate levels.

[rdavidw]

My 150 gallon reef tank has been running well for about twenty five years until about a year ago when I was out of the country for four months and had a total crash. I am now rebuilding with some frags and fish and thinking about addressing my mix of mostly outdated tech. My frags are growing well and fish are happy, but getting a Cyanobacteria outbreak from very low phos and nitrate levels.

Current parameters:
Salinity: 1.027
Calc: 425
Alk: 10.5
Mag: 1350
Ph: Stable between 8.3 and 8.4 (Have a Kalk stir on a pH controller and a Co2 Scrubber on a motorized ball valve also on the pH controller)
Phosphate: Reading 0.00 to 0.03 with Hanna UL Phosphate checker
Nitrates: 0 – Don’t have ultra low test kit yet

Filtration:
Overflow to a 30 gallon refugium with a 7” deep sand bed
Sump return pump feeds through a 40watt uv to a manifold to:

1. Display tank return
2. Carbon reactor
3. Biopellet reactor

All of the output from the biopellet reactor feeds into a Reef Octopus 150 external skimmer
Carbon reactor feeds to an adjustable portion between skimmer and sump to dial in skimmer throughput.
Skimmer feeds back to sump

I have a small clump of Chaeto in my deep sand bed refugium I use to monitor nutrient levels. If it starts to grow I add biopellets, if it starts to die I remove biopellets.

My small ball of Chaeto started to turn brown and die off so I pulled all but about a cup and a half of my biopellets. I also fed more Reef Roids with a cap full of Amino Acids. Still getting plummeting Phos and Nitrate levels; so I am now feeding unwashed frozen San Fan brand Brine Shrimp to dump high levels of phosphates and nitrates to the system.

One of my goals to make the tank as survivable as possible with only minimum maintenance, ideally only once or twice a month.

Rather then constantly changing the amount of feeding and or the amount of biopellets being run, would it be cleaner to just adjust the duration the skimmer is running each day? My understanding of biopellets, is that the reactor does not remove anything, it just nurtures bacteria that congeals the phosphates and nitrates for the skimmer to remove. If the skimmer is off, would that congealed bacteria then return to the display tank to feed the coral and elevate the Phosphate and Nitrate levels?

Thank you for any suggestions.

 

[odariel]

I think cutting down on your skimming hours during the middle of the day with a timer will help if you dont want to further increase your feedings. Also cutting light hours to your refuguim will help too... i would personally go the "feed more" route, i like the "high in / high export nutrient " but if you dont wanna do it, less skimmer and chaeto time makes sense... also, alk at 10.5 with such low nutrients... if you are not on top of them and they get reallly depleted, I think your are gonna burn the grow tips on your SPS, maybe lower it slowly until you get nutrients stable?

Edit: i wouldnt get the Low range Nitrate hanna tester.. any measurement of that kit is too low anyway.. the high range is more useful in my opinion and the testing is easier & faster

Also, why only frozen brine shrimp? krill and mysis have a higher nutritional value for your fishes -> tank

 

[Miami Reef]

If you want to increase nutrients, remove the biopellet reactor and feed more.

You can also dose food-grade Nitrate/Ammonium and Phosphate —Those would increase the nutrients quicker.

 

[rishma]

I would suggest that the chaeto canary in the coal mine isn’t accomplishing what you want. If you nutrients are too low, reducing the bio pellets or shutting off the reactor should help.

 

[rdavidw]

Fantastic suggestions from everyone. Thank you.

My skimmer run time is the easiest to control as I have it on a SmartThings app outlet. My biggest question is, to what degree will having the skimmer off negate the biopellets?

When the skimmer is off, the phosphates and nitrates that are bound to the bacteria that was knocked off the biopellets will pass up to the display tank. Will that bacteria then be consumed by the coral, or will it breakdown and be released, or will it just float around till the skimmer kicks back on?

My goal is to dial in automation so the tank can run about a month without being touched. I only stock a few fish that can live on pods and a dry food auto feeder.

Thanks again!

 

[Miami Reef]

I prefer having the skimmer on 24/7. It provides gas exchange and removes organics from the water.

The biopellet reactor is optional, and its sole purpose is to reduce nitrate. I would first turn off or restrict the output before touching the skimmer.

 

[Randy Holmes-Farley]

I prefer having the skimmer on 24/7. It provides gas exchange and removes organics from the water.

The biopellet reactor is optional, and its sole purpose is to reduce nitrate. I would first turn off or restrict the output before touching the skimmer.

I agree. Skim 24/7 and make some other change.

 

[rdavidw]

Based on the above advice, perhaps I should just remove the biopellet reactor and keep the skimmer on 24/7. My fear is the nutrients will spike and my biopellets bacteria is all dead, and it will take a long time to reestablish.

Perhaps I should go back to being a ganga farmer and let the chaeto grow out as the levels come up. I could then use the lighting times on the refugium to bring the nutrient levels up as needed.

My tank will always have a low bioload of fish, so running biopellets at all may be overkill. I would guess just running chaeto will be less aggressive then the biopellets.

 

[rdavidw]

Another thing to consider is that my fist sized chaeto ball was consistently green but not growing until I recently added a kalk stir reactor. I wonder if the new kalk precipitated out some of the little remaining phosphates and caused the chaeto ball to start to die off with the 0.00 phosphates reading?

 

[Miami Reef]

My fear is the nutrients will spike and my biopellets bacteria is all dead, and it will take a long time to reestablish.

Nah. Don’t worry about this. The bacteria can easily regrow and knock back the nutrients if you need it to in the future.

 

[rdavidw]

Biopellets are gone. Fingers crossed.

 

[odariel]

Don't worry, if you get a nutrient spike, your chaeto will take care of it growing faster, or worst case scenario, you can do a little bit of carbon dosing until they stabilize. then fine tune it with the amount of light hours you give your chaeto. Anyway, you know what you are doing and the possible ways to tackle any scenario, you just need to find what is more convenient / autonomous in the long run.

 

[rdavidw]

Yes Sir! Agreed. I have been running biopellets for about eight years, before that I was pulling out chaeto. With the biopellets, I seeing less algae growth on the glass and needed a smaller clean up crew but always had a bit of Cyanobacteria in the back corners of the display tank sand bed. Looking forward to going back to pulling chaeto with the improved pH stabilization and increased pods.

I have cameras on the display and sump area for when I am out of the country for months at a time. I also get text alerts on power out, on leak sensors and skimmer container full. I can call someone in as needed to clean the glass, skimmer, refill dosing, kalk and Co2 scrubber, refill auto feeder, do water test and so on. I got about two months to get things dialed in before I travel again. My goal is to only need to call them in about once a month.

 

[rishma]

Yes Sir! Agreed. I have been running biopellets for about eight years, before that I was pulling out chaeto. With the biopellets, I seeing less algae growth on the glass and needed a smaller clean up crew but always had a bit of Cyanobacteria in the back corners of the display tank sand bed. Looking forward to going back to pulling chaeto with the improved pH stabilization and increased pods.

I have cameras on the display and sump area for when I am out of the country for months at a time. I also get text alerts on power out, on leak sensors and skimmer container full. I can call someone in as needed to clean the glass, skimmer, refill dosing, kalk and Co2 scrubber, refill auto feeder, do water test and so on. I got about two months to get things dialed in before I travel again. My goal is to only need to call them in about once a month.

I am also out of country for long stretches, it has really changed my approach to reef keeping. I am gone every other month, but my tank is not totally self sufficient for a month at a time, my daughter still tests things weekly for me. The fact you aim to only have someone once a month is impressive! I have a new goal….

 

[Pistondog]

We dose ammonium bicarbonate for nitrate 7 to 10 ppm. Po4 always high, 0.3ppm. No more chaeto in dark fuge, just rock and rubble.

 

[rdavidw]

Setting the goal is the easy part.

I have had this tank running for over 25 years. My strategy is to use cheap but reliable automation wherever I can and keep only a few inexpensive fish and easy corals. My goal is to just keep everything alive till I get back. If someone needs to come sooner than the once a month I can call them as needed.

Right now the tank is out of balance and I am doing water test every three days. Hopefully I can get everything dialed in over the next two months.

 

[rishma]

Setting the goal is the easy part.

I have had this tank running for over 25 years. My strategy is to use cheap but reliable automation wherever I can and keep only a few inexpensive fish and easy corals. My goal is to just keep everything alive till I get back. If someone needs to come sooner than the once a month I can call them as needed.

Right now the tank is out of balance and I am doing water test every three days. Hopefully I can get everything dialed in over the next two months.

My current tank is only 3 yrs old and I also don’t have super high end corals or fish. I also use automation, and favor methods that require little intervention, and can be tuned based on quantitative data (tests, monitors, dosing pumps.) Been doing it this way for a year and the first few months were a mess but I learned.

When I am home I do a ton of tests, make small slow changes to carbon dosing and supplement dosing with the goal of being at steady state when I am gone. I have yet to spend a whole month away without having to make further adjustments via controller based on weekly tests.

 

[rdavidw]

That is part of the fun for me, the challenge of setting up something that I can monitor from China for three or four months at a time, with as little hands on support as possible.

 

[rdavidw]

Quick update. Four days after removing bio-pellets:

1) pH has shot up considerably - I have a Kalk reactor on a pH controller that drips in top off Kalk water, with a fresh water ATO float set lower then the Kalk float. After removing the bio-pellets, the sump level is slowly dropping to the fresh water float level. I am turning off my soda ash dosing to get back up to 100% Kalk water top off.

2) Phosphates are up from 0.00 to 0.04. Is 0.05 a good target?

3) My small patch of Cyanobacteria is totally gone.

4) Starting to get a green film on the display tank glass.

5) Chaeto is starting to green up and grow.

So far, happy with removing the bio-pellets.

 

[rdavidw]

OK, seven days after removing bio-pellets:
1) Phosphates shot up to 0.11
2) Significant outbreak of bubble algae in display tank and refugium (back has a live rock wall for pods)
3) Chaeto is still growing, but may take some time to catch up
4) Alk dropped to 8.1

The Alk drop is likely indirectly due to the pH increase from removing the bio-pellets. My Kalk stir reactor is on a pH controller. With the bio-pellets, 100% of the top off was Kalk water. When pH was high the water level in the sump would lower, increasing salinity. I was also dosing 75ml per day of soda ash at low pH times. With the bio-pellets removed, the Kalk reactor is cut off longer by the pH controller, and the water level drops below the fresh water top off float, so less then all of the top off is Kalk water. I moved the fresh water float down a little, but don't want the salinity to swing too much. I just switched dosing from to soda ash to sodium bicarbonate. This should allow the Kalk water to run more and get back to my Alk target.

To help the Chaeto catch up:
1) I added a 2nd cheap refugium light, one is on the top and one is on the side
2) Increased the refugium light cycle from 12 hours a day to 18 hours a day
3) Started dosing 18ml of Ferrion (iron fertilizer) every other day

I already have 5 emerald crabs in the 150 gallon display tank. I am going to get 5 more and also add 1 in the 30 gal refugium. I am also going to use a curved metal pick and a net and try to remove as much as the bubble algae as I can.

Coral, fish and inverts all seem happy. My hope is to grow out the chaeto to fill about half of the 30 gal (maybe closer to 20 gal with the 7" deep sand bed) and then pull out excess to keep it that size. I will also cut back the light cycle and Ferrion. Would like to keep the phosphates stable around 0.05.

Thank again for any suggestions; they are super helpful.