I need advice on nutrients.

[Velcro]

I have a 150 cube that is 95% acropora. It has been up a few months. The system is relatively simple for nutrient control... skimmer, big refugium with powerful horticulture LED and 10-15% weekly water changes.

Last week I switched from LED to halide. My phosphate has jumped from 0.12ppm to 0.38ppm (hanna ULR phosphorous) over the last 7 days. I THINK this is because I was running a 9AM-11PM photo period with the LED and I reduced it to noon-4PM when replacing the LED with halide. I have added 30 min every day since last friday to the photoperiod of the halide. I think the reduced photoperiod in the display caused some film algae death or something which spiked phosphates. There's really no other explanation for phosphate to jump that high as I have changed nothing else at all. Nitrates have been 16-32ppm on the red sea kit over this same 7 day time period. They are possibly slightly more toward the 32 than the 16 this week however.

Here's my dilemma. I could turn up my refugium photoperiod, but I'm afraid of starving the acropora. Even though the test kits show high nutrients I honestly feel like in the past when I increase my refugium photoperiod, even though the nutrients either stay the same or only go down slightly, my acropora takes a hit. It's like they chaeto consumes the organic form of the nutrients faster than acropora can and even though numbers are there on the test kit it's not showing the whole story...

I'd love to hear everyones' thoughts on this.

 

[Velcro]

Also please note that my alkalinity demand has been rock solid since adding the halide... it's the same as it was for the LED with that 14 hour photo period with just a 4-5 hour halide photoperiod.

 

[Velcro]

I'm going to add to this post with a bump.

I also wanted to note that 1-2 months ago my rock was covered with hair algae which has completely disappeared. I did add a pack from reefcleaners and noticed the algae really disappearing once I started seeing these tiny translucent white snails that must have spawned from the reefbreeders order. After the hair algae melted away, i even had a couple spots of bryopsis pop up which only lasted about 2 weeks then also are gone now.

My tank looks cleaner than ever (except from week one when it was fresh live rock and new dry sand). My chaeto has about half-filled my fuge but has stayed pretty much that same size for weeks now, yet I have all these nitrates and phosphates on my test kits.

Honestly thinking about pulling the chaeto offline for a while to see if my acros seem healthier without it.

 

[Amoo]

#REEFSQUAD

 

[Anirban]

The question is where do you want your nutrient??
If you want to go high nutrients with your halides then just leave it. If no then increase the photoperiod for chaeto such a way that it gives you your desired level. Your acros should be fine if you maintain a bit lower nutrient than what you have now. But too many shocks like light change and continuous nutrient fluctuation will do more harm So i would not do anything for atleast few months and let the system adjust everything with new light and then change something.

 

[mta_morrow]

#REEFSQUAD

I see what you did there!

Following along as I hope to learn something myself here

 

[Greybeard]

Chasing numbers is a fool's game.

As long as you're not experiencing nuisance algae problems... why worry about phosphates a bit higher than they used to be?

These days, it's easy to get rid of phosphates... you could put a bag of GFO in the sump, presto... no more phosphate. Of course, your acros are likely to RTN and die of shock... but hey, no more phosphate, right?

My point is this. You changed lighting. Give your tank some time to adjust to that change, before you start changing anything else. Complete your acclimation cycle, back to the original 'day' time... unless you intend to stop short of that... with the halides, you probably don't 'need' as long of a day.

Speaking of the light change... Why did you change it? I'm supposing you weren't getting the growth you wanted... why else would an SPS keeper switch to Halides these days?

The usual problem with halides is temperature. I'm hoping you're keeping a close eye on that... or that you added a chiller at the same time. I'm going to assume temp is stable.

Ok, so you're phosphate levels have risen a bit. The change in algae growth is the likely culprit, but who knows. You're talking about a rise of .2PPM. Relax. If the phosphate keeps rising, and you're uncomfortable with that, you might increase your water changes, until things stable back up. That seems to me to be an easy, cheap, gentle, and safe method of reducing phosphate temporarily, while your tank is getting used to the new light.

I don't like to change multiple things in an aquarium system rapidly. You've just changed lights. Let the tank equalize with the new lighting for a while before you start changing anything else. Keep an eye on that phosphate, as always... but unless it continues to rise, or if your corals start showing signs of stress, I wouldn't recommend doing anything about it. Give it some time.

 

[Scorpius]

You did a major change to your system like I did when I switched over completely to T5. I wouldn't change anything right now nutrient wise. Your Acropora are adjusting to the new light and photoperiod and the last thing they need right now is another big change.

Just ride it out and let things stabilize again.

The worst thing you could do right now is changing something.

Worse case scenario is increase your water change volume.

 

[DesertReefT4r]

1. how do your corals look since the increase in po4? Still looking good and happy? The. Dont worry about numbers.
2. Try a good old spiral PC lamp over the fuge amd see how growth is. A 24w 6500k PC bulb has always worked best for me. Having good growth with a 6500k 14w LED but half the COB chip died after a month, the red blue purple LED has not done the best for me at growing chaeto.

 

[jda]

The rise in phosphate is likely due to aragonite bonding with a new tank. If you used new sand (or new rock, not dry or dead), then it will bond up most of the early phosphate from the water column. Once it gets a bit more full, water levels in the tank will rise a bit... this can happen somewhat rapidly over time and then settle down as the rock acts like more of a buffer. Keep up your skimming and water changes and see if it moves... either way.

You can also have more P in the water since there is no algae around to use it up.

Chaeto can get growth limited by iron. Changing water can add enough iron if you change water enough. If not, then you need to add it. Lots of people cannot understand why their chaeto stops growing and most of the time it is because of iron.

 

[jda]

BTW - I use halides, like you probably know. My building blocks are at NSW levels at about .1n and .01p and everything thrives. Your corals now will get the best possible true nutrient (sugars from the zoox) from the halides. I would give this some time.

Also, do not rule out the impact of a young tank... all kinds of parameters can jump around quite a bit for no reason that you can figure out. You can sometimes chase this or that in a young tank and things just settle down all on their own and you never figure out why.

 

[Scorpius]

The 1st year is the worst for stability. Parameters can swing like crazy.

 

[NeverlosT]

macro can also be iodine limited. consider some light lugols dosing to try and encourage macroalgae

 

[Reefer40b]

I'm going to add to this post with a bump.

I also wanted to note that 1-2 months ago my rock was covered with hair algae which has completely disappeared. I did add a pack from reefcleaners and noticed the algae really disappearing once I started seeing these tiny translucent white snails that must have spawned from the reefbreeders order. After the hair algae melted away, i even had a couple spots of bryopsis pop up which only lasted about 2 weeks then also are gone now.

My tank looks cleaner than ever (except from week one when it was fresh live rock and new dry sand). My chaeto has about half-filled my fuge but has stayed pretty much that same size for weeks now, yet I have all these nitrates and phosphates on my test kits.

Honestly thinking about pulling the chaeto offline for a while to see if my acros seem healthier without it.

What LED is over your fuge? I would not pull your chaeto only back off your lighting period. I'm currently using a MARS 300 over mine. I think the algae die off is why your seeing a higher level of N/P. I would just let your tank settle in to the new lights, its possible the haildes bleached the algae, light shock maybe... idk Your chaeto could also be missing some trace elements for growth which was mentioned by others... I think if your doing weekly changes you will be just fine in this department though.

 

[Reef of Fillory]

In terms of chaeto growth and supplementation, I really liked the results that I saw in the past after implementing this TLF iron/manganese mix. I dosed it 1x/week into the fuge and it seems to have made a huge difference in refugium growth with no change in light schedule

https://www.saltwaterfish.com/product-two-little-fishies-iron-concentrate [By far the cheapest source I could find when looking previously]