How to manage high Alk and low nutrients

[InkedReefLady]

Current situation:
300 gallon mixed reef up for over a year and a half.
Alk: 10.92 dkh (consistently between 9-10.5)
NO3: 2.5
PO4: 0
pH: 8.0
Ca: 425
Con: 35

I had shut off the skimmer sometime in June as an experiment and our montis started to grow a lot faster and color was pretty good. GFO and ROX carbon was old(er) at this point. We were primarily feeding NLS pellets with the occasional frozen cube/mysis.

Fast forward about 2 weeks ago when we added a pair of dwarf angels and started to feed a lot more than we used to. I turned the skimmer back on, took off the GFO reactor (since I was out of GFO) and replaced the ROX in the reactor.

Within days, a lot of our montis were bleaching out and/or started to die. LPS like frogspawn, favia, echinata, are doing fine as are a lot of encrusting montis (weird, right?).

I did a 30 gallon water change yesterday (using ESV salt - no change from what we have always used). Alk was 8.85 in the new water. I tested again this evening and we're still at 10.92 dkh.

So, my question is: Do I not worry about the alk (since it has been consistently high), cut my losses and dose aminos/wait it out?; Do another couple of water changes to further reduce dkh?; Feed more?; Add more corals to help with Alk uptake?

Not really sure what to do at this point to make sure we don't lose any more corals. But my guess is since turning on the skimmer and replacing the ROX/getting rid of the old GFO has further reduced our nutrient load to the point where our corals are very upset.

BTW, coraline algae grows like crazy in the tank. Not sure if that matters.

Thanks for your suggestions!

 

[InkedReefLady]

Giving this a bump.

 

[Hemmdog]

Feed more, aminos are great too, I use Red Sea reef energy and acro power on my tanks. The alk isn’t that high, my 40b frag/growout tank has very similar parameters.

 

[InkedReefLady]

Feed more, aminos are great too, I use Red Sea reef energy and acro power on my tanks. The alk isn’t that high, my 40b frag/growout tank has very similar parameters.

I have Brightwell aminos on the way to give a try. I had read to go slow with dosing so as to not have an algae bloom.

I feel like I feed a ton already....may cubes and/or chunks of mysis and LRS Fish Frenzy 2x a day and soaked in Angellixer.

I wanted to add a few more corals soon, but was hesitant the new comers would get upset with alk that high. Maybe I am being too concerned?

It looks like in the last few days the setosa and another monti are getting some color back, but I didn't want to jump the gun with adding more corals and have a poor out come.

 

[Hemmdog]

I have Brightwell aminos on the way to give a try. I had read to go slow with dosing so as to not have an algae bloom.

I feel like I feed a ton already....may cubes and/or chunks of mysis and LRS Fish Frenzy 2x a day and soaked in Angellixer.

I wanted to add a few more corals soon, but was hesitant the new comers would get upset with alk that high. Maybe I am being too concerned?

It looks like in the last few days the setosa and another monti are getting some color back, but I didn't want to jump the gun with adding more corals and have a poor out come.

How many are you feeding though? My 90gal gets 4-6 cubes of mysis daily and reef frenzy on top of that. Nitrates are around 5.

 

[motortrendz]

You said in your post that the p04 was zero, y add a phosphate remover? Phosphates shouldn't be zero. Should always show something on the meter. I like mine at 0.04-0.15, I've noticed the best color and growth at this level with nitrates below 8. Your montis could be starving out which is why they're bleaching.

Dont be too concerned about the alk number at this point. I run mine at 10.5. stability is key. If its fluctuating alot then I'd worry. Higher all numbers also need to have higher nutrient and calcium/mag numbers as well.

 

[InkedReefLady]

How many are you feeding though? My 90gal gets 4-6 cubes of mysis daily and reef frenzy on top of that. Nitrates are around 5.

We have a block of mysis and I break off chunks (same for the LRS). I'm not sure how many cubes it would equal, but my husband says the tank looks like a snow globe when I feed. LOL!

 

[InkedReefLady]

You said in your post that the p04 was zero, y add a phosphate remover? Phosphates shouldn't be zero. Should always show something on the meter. I like mine at 0.04-0.15, I've noticed the best color and growth at this level with nitrates below 8. Your montis could be starving out which is why they're bleaching.

Dont be too concerned about the alk number at this point. I run mine at 10.5. stability is key. If its fluctuating alot then I'd worry. Higher all numbers also need to have higher nutrient and calcium/mag numbers as well.

I had the GFO in there, but it was really old (and was a precaution from a while ago). I'm not running any now, just carbon for clarity.

I'm starting to think they are/were bleaching due to me removing the old GFO and carbon (and nutrients were trapped in there). After removing the old nutrient source, everything started to crap out.

I'll focus more on getting nutrients up a little bit more.

It's so odd since back in the 90s, you wanted nitrate and phosphate to be zero and now we are not getting it high enough! Ha!

 

[motortrendz]

Filtration and testing recently has become so precise I believe zero back in the day was never zero. And the filtration wasnt good enough to actually do that.

Now or filters are so good zero really is zero and we realize that it's too clean and starved everything.

I use seachem flourish phosphorus to dose po4 when it gets too low. I thi k once you get it up a bit that you'll see a tank wide "thank you" lol.

 

[ScottB]

As to the ALK level not dropping:
a) For some reason, your corals are not consuming as much as before. Any kind of stress on them will do that. Low nutrient will certainly. PO4 of zero is a no-no. I dump a ton of food in my systems and still dose PO4. Don't go crazy correcting this, but get moving soon and gradually.
b) I find that if my magnesium is off, I get an imbalance between ALK & Ca. Do you have a recent magnesium test result?

 

[InkedReefLady]

As to the ALK level not dropping:
a) For some reason, your corals are not consuming as much as before. Any kind of stress on them will do that. Low nutrient will certainly. PO4 of zero is a no-no. I dump a ton of food in my systems and still dose PO4. Don't go crazy correcting this, but get moving soon and gradually.
b) I find that if my magnesium is off, I get an imbalance between ALK & Ca. Do you have a recent magnesium test result?

Mg end of last week was 1410 (Sailfert)

I need to get a new Hannah PO4 checker. My old one (and the high range) quit working a few years ago and I never replaced it. I need to get the low range checker. SeaChem always is yellow = 0. So, if there is something in there and it's low, I'm not sure how low.