Dosing PO4

tsav87 · Sep 1, 2017

I started my tank with dry rock. I cooked the rock but never got a PO4 reading. The tank has been up and running for about 4 months now and still no PO4.

My NO3 is ~5ppm. I have started to get overrun with what appears to be dinoflagellates as described by many sources on the web.

While searching for a cure, I have read in multiple places that if the PO4 is undetectable that dinoflagellates will occur. An imbalance of PO4 : NO3 perhaps?

I purchased Brightwell's NeoPhos in order to bring the PO4 levels up to at least 0.04ppm.

The instructions say that 1ml of NeoPhos will increase the PO4 of 1 gallon of water by ~1.2ppm.

Here's where I need some confirmation. In order to raise each 1 gallon of water from 0ppm to 0.04ppm I should use the following calculation(?):
1.2ppm / 0.04ppm = 30
1/30 = 0.033 (mL)

So I would dose 2.33 mL of NeoPhos to raise the PO4 of 70 gallons (estimated actual water volume) to 0.04ppm...?

0.033 x 70 = 2.33 mL

rockskimmerflow · Sep 2, 2017

Correct math to my eyes.

Also, you are on the right track to the best approach to handling dinoflagellates that I've found. I know it sounds crazy, but if you have no hair or green turf algae I would highly recommend seeding the tank with some along with a variety of pods - especially munnid isopods if you can find someone locally who has them. Building a healthy balance of green algaes that are managed by grazing pressure seems to stabilize tanks that were suffering from dino due to low nutrients. Of course keeping the nitrates and phos in balance longterm is the key once you've established more competitive biodiversity.

Best of luck!!!

tsav87 · Sep 2, 2017

rockskimmerflow said:
Correct math to my eyes.

Also, you are on the right track to the best approach to handling dinoflagellates that I've found. I know it sounds crazy, but if you have no hair or green turf algae I would highly recommend seeding the tank with some along with a variety of pods - especially munnid isopods if you can find someone locally who has them. Building a healthy balance of green algaes that are managed by grazing pressure seems to stabilize tanks that were suffering from dino due to low nutrients. Of course keeping the nitrates and phos in balance longterm is the key once you've established more competitive biodiversity.

Best of luck!!!

Thanks!

Yep I read that too, about increasing biodiversity. I ordered a combo pack from Algae Barn. Comes with 4 different types of pods, over 5000 total and a bottle of phyto to help boost their population.

Luckily I do have some GHA growing. It came from a few frag plugs.

tsav87 · Sep 2, 2017

I tested this morning and got a reading of 0.02 ppm. It could be 0.04 ppm because the kit has an accuracy of +\- 0.02 ppm. I guess it also could be zero...ha!

The bottle did instruct to test after 24hrs. So I will test again tonight around the same time I dosed last night.

Sagecritter4life · Sep 2, 2017

Hesitate to comment because regardless of bottle instructions every tank seems different on dosages...chuckle

I have been slowly dosing for weeks trying to get up to .05-1 on my tank with 85 gallon water and after slowly increasing nightly dosage finally there on a MI 412 but it's taking 9ml to keep between .05-.09 reading.

Which by bottle should be about .12 reading.

So dosage is questionable based on daily uptake etc.

tsav87 · Sep 2, 2017

Is PO4 going to be stable? Or will I need to continue dosing?

I guess if it was continual, the dosage would become less and less as I add more fish which would cause me to feed more.

I know for what ever reason, my NO3 is rock solid. Unless I perform a large water change, the value remains the same.

tsav87 · Sep 2, 2017

Just tested again. PO4 is 0.01 ppm.

So something is absorbing the PO4.

I dosed again and have increased it to 3ml. I will check once more tonight to see if it spikes up to the 0.06 range and test again tomorrow to see if it gets used up again.

I ran about 36 hours total lights out, just dosing NeoPhos last night and my skimmer was reddish brown and stinkier than normal this morning. The rocks are completely free of any dinos. I am too chicken to go another 36 hours with no light, my corals are looking off so its back to being lit. However, I set the LEDs to be mostly actinic. I'll do that for a few days until I confirm that the dinos do not return.

tsav87 · Sep 2, 2017

Side note. Our Turbo snails are starting to cruise around again. I have read that dinoflagellates will cause them to be sluggish and possibly die. So hopefully, this is a sign that things are getting better.

tsav87 · Sep 2, 2017

Tested again. Nice to see my calculations/best guess working out. Lol. PO4 sitting at ~0.06. The color is darker than 0.04 but lighter than 0.08 on the red sea pro kit.

Will test again tomorrow after a normal day of lights and feedings and see where we end up.

tsav87 · Sep 3, 2017

This morning's test results before lights on.

PO4 0.04ppm
NO3 8ppm

What ratio of PO4 to NO3 do you all try to maintain?

Randy Holmes-Farley · Sep 3, 2017

Those values seem ok to me, although phosphate could be a bit lower. I do not consider the ratio between them to be the best way to think about it. Just because one is very high or very low is not a reason the other should be similarly very high or very low.

tsav87 · Sep 3, 2017

So let phosphate fall to 0.02ppm?

Sagecritter4life · Sep 3, 2017

tsav87 said:
This morning's test results before lights on.

PO4 0.04ppm
NO3 8ppm

What ratio of PO4 to NO3 do you all try to maintain?

I'm trying personally for 3-5 NO3 and .06-.15 on Po4

I'm order to stay there since my tank really REALLY light load I'm dosing refine (no3 @ 20 ml nightly) and 7-9 ml neophos.

I'm guessing that yes as you feed more and stock heavier you may find yourself dosing less and less. I lack sand clean up crew like nassarious/crabs etc and chose to liquid dose versus feed more fouling sand quicker.