SPS health observation

Scott.h · Apr 8, 2017

I have two frags in particular, newly introduced over a month ago. These frags came from really high par systems (for aguments sake say +500 par). I've taken on Dana Riddles approach to lighting. I have an adjustable 4' , 8 bulb T5 light over a 4' tank. It's overkill, but it's turned way down. 50%. So at peak I'm around 200 par.

Two things.. first of all my nitrates and phosphates are unreadable, so I've been forced to start dosing nitrate, which isn't yet dialed in. There are two corals in particular that are lighter then they should be, I believe due to this. No big deal as of yet. No tissue loss, and they are still starting to grow over the superglue.

Secondly I'm wondering how giving lower par is currently working in relation to the low nitrates. Maybe I'm having better luck with lower par on higher light coras because of lower nutrients? Things I've been pondering.

This morning I was around when my first two light bulbs turned on. (Two bulbs.. purple and actinic) which ramp up over an hour before the other six bulbs kick on,.. then those 6 also ramp up for another hour. With only two bulbs on, these 2 pale corals have thier polyps full extended at very low light conditions, yet are about 50% more pale towards the base then they should be.

Lastly I'm wondering if I go ahead and feed those corals early when they are polyps are extended, if that will supercharged them, so to speak, and create them to pale all even worse when my lighting is higher, given my current nitrate reading.

Any thoughts from the experts on these theories?

Paullawr · Apr 8, 2017

Hi Scott

This is an age ole issue with low nutrient systems.

Firstly i wouldn't crack the light up whilst they are pale. It will over stress them.

Keep lighting as is for now. Continue to dose the potassium nitrate or sodium nitrate and over the next month monitor their improvement.

Feeding more.can have an adverse effect in phosphate and whilst you want some you don't want to spoil the water either.
By all means try it but don't go nuts.

Once nutrient is ok (i aim for 2-5ppm nitrate) then they should start to bounce back.

I'm sure there's a whole host of people that can offer good advice in this area but this worked for me.

Scott.h · Apr 8, 2017

My plan is to dose nitrate two times a day until I can see pink from the side through the glass. The problem with this is every time I can see pink it dissipates. I'd like to get it dialed in so I can add "x" potassium nitrate to my 5 gallons of top off water and be done... test once a week.

One main question i have is if these corals are supposed to need 300+ par, why do they respond so well with their polyp extension with such low par? And will they need more then 200 eventually? It doesn't appear so.

And second, will spot feeding cause them to lighten worse when they aren't being spot fed given the situation?

I have several corals that aren't effected, and despite the undetectable levels I know there is a good deal of nitrate present by the algae growth on the glass. The corals are just sucking up before I can read it.

Scott.h · Apr 8, 2017

Only two.. lights now all the way up. They look a little lighter in person then with the camera. Like I said, higher nitrates will fix this part, I know. Just an observation along the way of the other part.

Paullawr · Apr 8, 2017

The polyp extension is because they are hungry. I had some of my sps basically turn cream with full PE .

After dosing and dialing in the amount they PE less but look better for it.

Paullawr · Apr 8, 2017

Lovely frags btw.

Paullawr · Apr 8, 2017

Spot feeding won't be detrimental to the coral just be careful now to swing the water the other way. Clean water isn't just dissolved organics. I ran a really good nano tank with nitrates somewhere between 5 an 10ppm which is considered high.
True, i probably didn't have the sharpest colouration but they looked well and grew.