Proper nutrient levels. LPS vs. Algae

[Meloco14]

Hi all, I am struggling with a couple LPS frags, I've posted about it a couple times and the concensus is my nitrate and phosphate are likely too low for them to thrive. Most recent nitrate was between 0 and 5ppm (API test) and phosphate is .02 according to an ICP test I got back 2 weeks ago. Hanna phosphate shows 0. I turned off my skimmer, increased feeding, removed some chaeto from the fuge and reduced the lighting schedule on the fuge, but levels have not risen. I bought some neophos and neonitro to dose, but before doing so want to ask this. Won't doing this increase my nusiance algae? Tank is 5 months old and has diatoms starting on the sand and cyano in the fuge. Diatoms have spread since I stopped skimming. If I dose nitrate and phosphate to try to help my corals won't I also fuel the algae? Or will the coral outcompete the algae for the nutrients? I feel like there's no good answer, either keep nutrients low to minimize the uglies, at the risk of losing frags, or try to help the frags at the price of increasing the bad algaes. Am I missing something or am I just stuck in a bad position?

 

[Nano sapiens]

How often do you feed your LPS? Feeding 2-3x/wk should give them the nutrients that they need. Target feeding a good quality amino acid supplement can also help in a low nutrient environment.

 

[Meloco14]

How often do you feed your LPS? Feeding 2-3x/wk should give them the nutrients that they need. Target feeding a good quality amino acid supplement can also help in a low nutrient environment.

I feed between 1-3 times a week. Definitely not consitently enough. That makes sense though, if I stay consistent on feeding I can limit the overall nutrients. And yes I use amino acid supplements with the coral food. Thank you!

 

[jda]

It doesn't really matter what you residual levels of N and P are, as long as they are detectable then they are not growth limiting on the low end (too high can be a problem, but not at your levels). If you want your corals to thrive, feed the fish... a lot. The ammonia/ammonia will help the coral more than anything else that you are doing. This can cause N and P to rise on the back end if you do not have export mechanisms, but you can export heavy to match heavy feeding and not help the algae too much.

All of this said, I feed heavy, export heavy and have natural level of residuals (.1N and .005-.01P) and algae will grow very well in my tank if I don't have consumers - I find that fish are worthless most of the time, but urichins, ceriths and astrea snails are voracious algae eaters in tanks with good water quality. I have a diverse and mature tank, so dinos and cyano are not a issue for me - the aminos that you are dosing are good fuel for matting bacteria which get more of the dosage just by simple math (more surface area).

In the end, if you want your LPS to do better, then feed the fish... don't dose on the back end. Read up on what corals have to do to utilize nitrate for nitrogen - most have to covert it back into ammonia/ammonium which is expensive and not even all of them can do this.

 

[Meloco14]

It doesn't really matter what you residual levels of N and P are, as long as they are detectable then they are not growth limiting on the low end (too high can be a problem, but not at your levels). If you want your corals to thrive, feed the fish... a lot. The ammonia/ammonia will help the coral more than anything else that you are doing. This can cause N and P to rise on the back end if you do not have export mechanisms, but you can export heavy to match heavy feeding and not help the algae too much.

All of this said, I feed heavy, export heavy and have natural level of residuals (.1N and .005-.01P) and algae will grow very well in my tank if I don't have consumers - I find that fish are worthless most of the time, but urichins, ceriths and astrea snails are voracious algae eaters in tanks with good water quality. I have a diverse and mature tank, so dinos and cyano are not a issue for me - the aminos that you are dosing are good fuel for matting bacteria which get more of the dosage just by simple math (more surface area).

In the end, if you want your LPS to do better, then feed the fish... don't dose on the back end. Read up on what corals have to do to utilize nitrate for nitrogen - most have to covert it back into ammonia/ammonium which is expensive and not even all of them can do this.

Interesting, thank you for the thorough reply. It's confusing because when my corals were declining and I posted my parameters the consensus was low nutrients. But of course I know nutrients fuel algaes, so it was kind of a catch 22. Just didn't make sense to me to increase the algae fuel, but of course I want to save the corals. Over the last couple weeks I have reduced export, increased feeding both fish and corals, and even dosed neonitro and neophos very lightly twice. Nitrate and phosphate never went up, in fact nitrate went down. But the nusiance algae and cyano has increased. Probably in part due to the coral feeding as you suggest, because I did notice that the algae spots started around the frags I was feeding. And all this time no noticeable health benefit to the corals I was trying to help in the first place. I will go back to exporting more heavily to slow the algae growth, and just feed fish heavier and occasionally spot feed the few struggling corals. Most likely it just needs more time to balance out. I have 2 more fish finishing quarantine so that will help bioload a bit when they go in the display. That will bring it to 5 small fish in a 90gal display, not much bioload for feeding LPS I'm guessing. Thanks again for the advice.

 

[DxMarinefish]

Feed the fish until they are fat and then some.

Get yourself a good number and mixture of CUC, they are as vital to any system as food is to the fish and corals.

have multiple export mechanisms, the more natural the better.

eventually it’s stability you should be aiming for and most corals will adapt to stability.

Don’t chase numbers.

 

[Meloco14]

Feed the fish until they are fat and then some.

Get yourself a good number and mixture of CUC, they are as vital to any system as food is to the fish and corals.

have multiple export mechanisms, the more natural the better.

eventually it’s stability you should be aiming for and most corals will adapt to stability.

Don’t chase numbers.

Yes I am trying to commit to this. As soon as things don't go well I search for the reason, something must be off, but in reality I need to let the environment stabilize and take care of itself. In hindsight the tank was not ready for certain frags, which I didn't know at the time, but now I know to wait and go with what the tank is ready for, instead of trying to change the tank to work with what I want. Thanks for the advice.

 

[littlefishy]

As was mentioned above, emerald crabs are voracious algae eaters. You will lose all desirable macro with them if you have any.