Restoring from tank crash. Continue increasing nitrate/phosphate dosing?

[kwirky]

A car accident last October led to some poor husbandry for half a year. I couldn't do water changes and driving to pick up consumables was difficult. I've recovered a substantial amount and the acro & monti colonies I have left are starting to colour back up now that I have things under better control and my schedule is mostly back in effect. The last thing I'm dealing with is a nutrient defficiency and am wondering if I'm being impatient while waiting for things to colour back up or if I should bump my nitrate and phosphate dosing up. I'm thinking that I should bump up my nitrate and phosphate dosing until it's detectable with the hanna checkers but I'm worried about causing some sort of problem with nuisance algae (particularly the spirulina) if I do that.

I'm including a lot of info about lighting because it goes hand in hand with nutrient consumption and coral colours. because things like lighting and nutrient consumption go hand in hand. Hopefully it's not too much information. I'm starting a separate thread because this isn't about how safe it is to dose dry fert nitrate/phosphate daily, like my other thread was discussing.

Water parameters & maintenance:​

• Approx 500L of water volume in tank & sump, with displacement from rocks.
• 10% weekly changes with aquaforest reef salt at 1.025 (refractometer)
• Carbon in reactor changed monthly.
• dkh 7.1 (steady for a couple months now, hanna checker)
• calcium 410 ppm (salifert)
• magnesium 1400 (salifert)
• nitrate: still 0.0 undetectable at 11pm when lights are out, with hanna high range checker, despite dosing. confirmed with salifert kit.
• phosphate: still 0.0 undetectable at 11pm when lights are out, with hanna high range checker, despite dosing

What I'm auto dosing:​

• Aquaforest 3 part pro calc/alk/mag + micros, dosing pump, 24 x per day
• Equivalent of 1.5ppm of nitrate (potassium nitrate) over the period of 11am to 11pm, dosing pump (calculated with this)
  • Started auto-dosing this approx 2 weeks ago
  • Thinking of increasing by 1ppm each week until detectable
    • basically increase of 1g kno3 in my 500L water volume daily
• Equivalent of 0.15ppm phosphate (potassium phosphate) added daily over the period of 11am to 11pm, dosing pump (calculated with this)
  • Started auto dosing this approx 2 weeks ago
  • Thinking of increasing by 0.1ppm each week until detectable
    • basically increase of 0.1g potassium phospphate in my 500L water volume daily

Pest algae currently in tank:​

• A bit of bubble algae.
  • Used to be under control but my emerald crabs died off during the slow crash. Local LFS stores haven't been able to restock emeralds. Will get more when I can.
  • Growing in deepest depths of birdsnest and poci colonies. Haven't seen any on pumps or rocks.
• Spirulina
  • growing on dead coral skeletons, some bare rocks, some parts of bare glass bottom
  • identified via hydrogen peroxide test of a sample

Coral colour progress examples (no photos ATM, sorry):​

• sunshine monti: gaining a bright green colour on the new growth polyps and the old growth changed from brown to mid green. hint of red in the new growth areas finally.
  • Should return to full colour at this pace in 6-10 months. This feels very slow.
  • receives 300-350 par light
• unidentified green deep water acros, various colonies: all are either back to full colour with purple new growth tips or will return to full colour within 6 months which feels slow.
  • receive 200-350 par light.
• Green poci: full bright green restored
  • receives 250 par light
• Pink poci: used to be pale, now slightly pink but not the bright acidic pink they used to be yet. Haven't seen change transition beyond current pinkishness
  • receives 250 par light
• green birdsnest: body surfaces now restoring green but it's still pale on 50% of the surface. Expect to colour up in a few months now and not concerned, this stuff's bullet proof.
  • Polyps have always been brown, not expecting polyps to change.
  • receives 250-400 par light

Lighting:

Decreasing my lighting by 100 par a month ago helped stop the acro bleaching from continuing further. I kept my kH stable throughout the lighting changes. I turned off my aquatic life hybrid LED fixture a month ago because they added little light and lots of heat & humidity.

• 350-400 par peak at highest points of rock work now (used to be 450-500 peak)
• 2x Reef Brite XHO actinic which provide approx 250-300 par throughout upper 10" of tank, on 4 hours.
• 2x hyperreef 150. On at 5% white/blue 11am and off at 11pm.
  • Adds 100-150 PAR at peak 2 hour period, depending on location in tank
  • Blue channel Follows bell curve, ramps up and down over 6 hour period, with minimum 25% brightness for 6 hours and peaks for 1-2 hours at 40% brightness
  • White channel follows bell curve, ramps up and down over 6 hour period, with minimum 10% brightness for 6 hours and peaks for 1-2 hours at 18% brightness.

 

[Randy Holmes-Farley]

I see no reason to not feed more or dose nitrate and phosphate when they continually read none.

I'd manually remove any cyano you have.

 

[brandon429]

post tank pic showing sandbed cross section if applic, required for long term forecast=the tank pic with the params.

 

[brandon429]

reason why: eutrophication prevention. crash recovered tanks that retain the original invasion mass/killed off by additives or renewed husbandry/are often littered with waste (apparent in some pics) that degrade into alternating generations of invasions, starting with cyano > dinos> back to gha then coral incursion losses, in a very high % of restoration jobs we have on file

exporting that decay is nearly required for long term success... much like a dentistry run occasionally at least is required for mouth and teeth success especially after challenge events and/or advanced aging of the system. how you deal with particulate waste is the hidden risk, long term. we have threads on specific crash recovery biology, curious how your pics lines up with the ones we already have on file as before and afters

 

[kwirky]

What I was worried about happening has happened. I increased my potassium nitrate additions to the equivalent of 2ppm per day, 2g potassium nitrate per day dissolved in RODI, dosed with the dosing pump. This was from 1.2g per day when I first started this thread.

As of last night my alkalinity crashed from 7.1 to 6.5, likely due to the increased consumption due to increased nutrients. It was at 7.1 4 days ago. My calcium crashed from 410ppm to 350ppm over the 4 days. Magnesium fell from 1440 to 1380. This measurement was as of last night at 11pm when the lights were out. I tested ahead of my weekly schedule because I saw yet another small colony bleach and grow over with cyano/spriulina within 24 hours, the fastest I've seen in a while, so I figured something's wrong.

Here's a photo of the tank after 1 week of growth on the bottom and 2 days without scraping the glass. Last Monday night I scraped and siphoned out the purple growth off the bottom, used a toothbrush and worked off most of that which was on the rock, and removed about 1 gallon of sand. This is what it's like a week later. I scraped my glass 2x this week, this is the glass after a couple days. I have an auto-roller if that's relevant information. I used to scrape less off the glass than this once a week, now I get this much every couple days, if that's relevant to anybody.

I've learned from @Randy Holmes-Farley that I shouldn't be using potassium nitrate long term so I have been calling around plus searching online and haven't found a local or canadian source for sodium nitrate nor calcium nitrate that's not $20/kg to ship. Because I can't find a good dry chemical nitrate source, I'm thinking of getting an auto feeder back on the go and feeding the daylights out of the tank. All my fish readily eat Vitalis Platiunum Marine 1mm soft pellets as of a few months ago so I now have a food I can auto-feed (compared to frozen mysis).

Here's what I'm going to do for the short term, in order, while I have this week off:

1. Cease the potassium nitrate dosing because it'll build up potassium long term.
2. Correct my alkalinity and calcium deficiency over the next few days, starting today
3. Test my alkalinity DAILY for the next month so I can catch these changes immediately and not when I see loss of coral life.
4. Remove the last of the sand bed.
5. Completely remove the large rock in the rear left of the overflow which never seems to grow coral in that position and just grows algae (has been problematic since the tank was set up).
6. Clean all the pumps and powerheads in bleach then citric acid (not all at once). Get through them all over a week.
7. Install more powerheads to keep the bottom flushed of debris.
8. Set up an auto-feeder and first tune it to feed the same amount I've been feeding by hand on the same schedule.

Some things I'm looking for advice on:

• Advice on a readily available carbon for my fluidized reactor. I'm using marineland which stops tumbling within a week, even with a larger pump installed. Please name a few brands if possible because there are shortages here in Canada post-covid.
• Since I won't have a sand bed should I add another marinepure 8x8x4" block to the sump? Or more than that?
• Should I try to trap the melanarus wrasse and take it back to the store? or risk the melanarus with hermits and hope it doesn't eat them?
• Should I let my powerheads kick up the tank throughout the night and keep detritus waterborn up or should I reduce my flow at night time to let the fish rest?

 

[brandon429]

This is a direct match to the status of your reef post crash

Notice this inversion to your current plan: it's not that adjusting parameter levels fixes the tank

Its that physical export of waste and target surgically, not chemically, restores parameters

By rip cleaning your tank you fix the parameters, your level of physical mass is a near match to his before the rip clean. The loss mass inside the tank isn't bad but that makes it easily removable as well, if you only take the chemistry route the surface area in the system slowly plugs up over time vs the skip cycle deep clean which restores the entire system in one day, all pores opened and breathing

Check out his parameter reports and coral health after the rip clean

Build Thread - Deep Reset, Reviving my 80 gallon lowboy.

Wanted to start a new thread to hopefully keep track of things as the new tank build progresses. As well as for a little extra added motivation to follow through. Real quick this is the same tank from that crazy instacycle- instastock- full tank transfer- call it whatever you want to call it...

www.reef2reef.com

 

[kwirky]

Yeah today i did a lot. Ripped out most of the sand and it was aweful. To my eyes it looked like the sand was 50% detritus. I pulled out about 20% of the rockwork to open it up, and as you can see from the photo it is much more open. I siphoned what cyano i could directly and razored and toothbrushed off everything else. I yanked about a pound of capnella from rocks and the sand bed, easy nutrient export .

The auto roller is triggering 2x a minute and is working like a champ polishing up what is drifting in the water.

The skimmer was absolutely nasty, 1/2" thick brown and like toothpaste inside the neck and cup. That was cleaned right out.

It was about a 30% water change today for this work. I'm going to go at it again tomorrow, with another 30% change and more sand siphoned.

I still have to clean powerheads and pumps, too. I have a couple jebao powerheads i'll point at the rear floor once the last of the sand is out.

I'm on my way to the lfs now to see what they have for hermits.

 

[Randy Holmes-Farley]

What I was worried about happening has happened. I increased my potassium nitrate additions to the equivalent of 2ppm per day, 2g potassium nitrate per day dissolved in RODI, dosed with the dosing pump. This was from 1.2g per day when I first started this thread.

As of last night my alkalinity crashed from 7.1 to 6.5, likely due to the increased consumption due to increased nutrients. It was at 7.1 4 days ago. My calcium crashed from 410ppm to 350ppm over the 4 days. Magnesium fell from 1440 to 1380. This measurement was as of last night at 11pm when the lights were out. I tested ahead of my weekly schedule because I saw yet another small colony bleach and grow over with cyano/spriulina within 24 hours, the fastest I've seen in a while, so I figured something's wrong.

Here's a photo of the tank after 1 week of growth on the bottom and 2 days without scraping the glass. Last Monday night I scraped and siphoned out the purple growth off the bottom, used a toothbrush and worked off most of that which was on the rock, and removed about 1 gallon of sand. This is what it's like a week later. I scraped my glass 2x this week, this is the glass after a couple days. I have an auto-roller if that's relevant information. I used to scrape less off the glass than this once a week, now I get this much every couple days, if that's relevant to anybody.

I've learned from @Randy Holmes-Farley that I shouldn't be using potassium nitrate long term so I have been calling around plus searching online and haven't found a local or canadian source for sodium nitrate nor calcium nitrate that's not $20/kg to ship. Because I can't find a good dry chemical nitrate source, I'm thinking of getting an auto feeder back on the go and feeding the daylights out of the tank. All my fish readily eat Vitalis Platiunum Marine 1mm soft pellets as of a few months ago so I now have a food I can auto-feed (compared to frozen mysis).

Here's what I'm going to do for the short term, in order, while I have this week off:

1. Cease the potassium nitrate dosing because it'll build up potassium long term.
2. Correct my alkalinity and calcium deficiency over the next few days, starting today
3. Test my alkalinity DAILY for the next month so I can catch these changes immediately and not when I see loss of coral life.
4. Remove the last of the sand bed.
5. Completely remove the large rock in the rear left of the overflow which never seems to grow coral in that position and just grows algae (has been problematic since the tank was set up).
6. Clean all the pumps and powerheads in bleach then citric acid (not all at once). Get through them all over a week.
7. Install more powerheads to keep the bottom flushed of debris.
8. Set up an auto-feeder and first tune it to feed the same amount I've been feeding by hand on the same schedule.

Some things I'm looking for advice on:

• Advice on a readily available carbon for my fluidized reactor. I'm using marineland which stops tumbling within a week, even with a larger pump installed. Please name a few brands if possible because there are shortages here in Canada post-covid.
• Since I won't have a sand bed should I add another marinepure 8x8x4" block to the sump? Or more than that?
• Should I try to trap the melanarus wrasse and take it back to the store? or risk the melanarus with hermits and hope it doesn't eat them?
• Should I let my powerheads kick up the tank throughout the night and keep detritus waterborn up or should I reduce my flow at night time to let the fish rest?

There is clearly test error involved here, and possibly or not, anything else happening.

Several comments:

1. Alk drop from 7.1 to 6.5 is hardly a crash. A pickup in demand is the way i'd word it. Dose more.

2. Never dose potassium nitrate long term. It will cause excess potassium unless you do a lot of water changes to keep it down. Sodium nitrate or calcium nitrate are far better choices. Feeding more is also good when those are not available.

3. Nitrate dosing boosts alk. 2.3 dKH per 50 ppm of nitrate dosed and consumed.

4. With an alk drop of 0.6 dKH, calcium dropped only about 4 ppm. The drop you see if for other reasons, such as tst error or a salinity drop (unless you have been dosing the nitrate for months).

 

[kwirky]

There is clearly test error involved here, and possibly or not, anything else happening.

Several comments:

1. Alk drop from 7.1 to 6.5 is hardly a crash. A pickup in demand is the way i'd word it. Dose more.

2. Never dose potassium nitrate long term. It will cause excess potassium unless you do a lot of water changes to keep it down. Sodium nitrate or calcium nitrate are far better choices. Feeding more is also good when those are not available.

3. Nitrate dosing boosts alk. 2.3 dKH per 50 ppm of nitrate dosed and consumed.

4. With an alk drop of 0.6 dKH, calcium dropped only about 4 ppm. The drop you see if for other reasons, such as tst error or a salinity drop (unless you have been dosing the nitrate for months).

1. Yeah i tested it a 2nd time with my salifert kit to double check the value before adjusting then calculated the new dose amount. I keep wondering if i should get a calcium reactor but the ease of these sorts of adjustments when using a dosing pump remind me to not head doen that road.

2. Yeah i found your other thread where tou stated calcium nitrate > sodium nitrate > potassium nitrate. I found a calcium nitrate from amazon but it's 15% nitrate and 1% ammonia, so like you had said, it's difficult to find in a pure form.

3. Can you explain this further? How does nitrate dosing boost alkalinity? Is it something you've witnessed or something you've calculated?

4. The calcium kit isn't expired but is down to the last 5% so it's likely time to replace it.

 

[Randy Holmes-Farley]

3. Can you explain this further? How does nitrate dosing boost alkalinity? Is it something you've witnessed or something you've calculated?

It's an unavoidable aspect of consuming nitrate. this article discusses the more general cse of the nitrogen cycle, but when dosing nitrate, you are only doing the second section starting in bold below.

When Do Calcium and Alkalinity Demand Not Exactly Balance? by Randy Holmes-Farley - Reefkeeping.com

Alkalinity Decline in the Nitrogen Cycle

One of the best known chemical cycles in aquaria is the nitrogen cycle. In it, ammonia excreted by fish and other organisms is converted into nitrate. This conversion produces acid, H+ (or uses alkalinity depending on how one chooses to look at it), as shown in equation 1:

(1) NH3 + 2O2 --> NO3- + H+ + H2O
For each ammonia molecule converted into nitrate, one hydrogen ion (H+) is produced. If nitrate is allowed to accumulate to 50 ppm, the addition of this acid will deplete 0.8 meq/L (2.3 dKH) of alkalinity.

However, the news is not all bad. When this nitrate proceeds further along the nitrogen cycle, depleted alkalinity is returned in exactly the amount lost. For example, if the nitrate is allowed to be converted into N2 in a sand bed, one of the products is bicarbonate, as shown in equation 2 (below) for the breakdown of glucose and nitrate under typical anoxic conditions as might happen in a deep sand bed:

(2) 4NO3- + 5/6 C6H12O6 (glucose) + 4H2O --> 2 N2 + 7H2O + 4HCO3- + CO2

In equation 2 we see that exactly one bicarbonate ion is produced for each nitrate ion consumed. Consequently, the alkalinity gain is 0.8 meq/L (2.3 dKH) for every 50 ppm of nitrate consumed.

Likewise, equation 3 (below) shows the uptake of nitrate and CO2 into macroalgae to form typical organic molecules:

(3) 122 CO2 + 122 H2O + 16 NO3- --> C106H260O106N16 + 138 O2 + 16 HCO3-

Again, one bicarbonate ion is produced for each nitrate ion consumed.

It turns out that as long as the nitrate concentration is stable, regardless of its actual value, there is no ongoing net depletion of alkalinity. Of course, alkalinity was depleted to reach that value, but once it stabilizes, there is no continuing alkalinity depletion because the export processes described above are exactly balancing the depletion from nitrification (the conversion of ammonia to nitrate).

There are, however, circumstances where the alkalinity is lost in the conversion of ammonia to nitrate, and is never returned. The most likely scenario to be important in reef aquaria is when nitrate is removed through water changes. In that case, each water change takes out some nitrate, and if the system produces nitrate to get back to some stable level, the alkalinity again becomes depleted.

If, for example, nitrate averages 50 ppm at each water change, then over the course of a year with 10 water changes of 20% each, the alkalinity will be depleted by 1.6 meq/L (4.5 dKH) over the course of that entire time period. This process is one of the primary reasons that fish-only aquaria that often export nitrate in water changes need occasional buffer additions to replace that depleted alkalinity.

While the magnitude of the depletion described in the paragraph above is fairly easy to understand, it also can be converted into units that clarify the imbalance. The impact of alkalinity depletion on the calcium and alkalinity demand balance depends, of course, on the amount of calcium and alkalinity added (and consumed) over the course of that same year.

For a typical reef aquarium (assuming a daily addition of saturated limewater equal to 2% of the tank's volume), the amount of alkalinity added during the course of a year is 297.8 meq/L. Likewise, the amount of calcium added is 5,957 ppm Ca++, given the ratio of 1 meq/L of alkalinity for every 20 ppm of calcium that has been discussed above. If that 1.6 meq/L of alkalinity is added to create a larger demand of 299.4 meq/L over the course of a year, the new ratio for the total demand becomes 19.90 ppm Ca++ per 1 meq/L of alkalinity. Consequently, while this effect of nitrate production on alkalinity is enough to be noticed over the course of a year, it is substantially smaller than the other effects discussed in this article, and is unimportant for aquaria that maintain low nitrate levels.