Some quick questions about tank water parameters

[Jcald327]

So, I've always battled hair algea and phophates in general because I came from freshwater land (alright I might be a bit lazy too), and my brain said treat your bacteria like a plant. If there is enough of an excess, for long enough, eventually the bacteria population will reflect, and the system will self balance. (So now that I'm changing filter socks every 2 days, and doing bi-monthly 20 percent changes, I think you can all assume I learned my lesson)

So system background
240g tank (8'x3'x18inches)
70 gal sump
2x 50 micron filter socks (washed every 2 days)
Royal exclusive bubble king mini 200 drawing outside air
Small regugium (rebuilding my cheeto currently, I basically wiped everything 3 weeks ago because of flatworms, hair algea, and a filter mat that I must have thrown in there a year ago being disgusting)
Brs dual reactor running full blast with about 2 cups of gfo 2 cups of carbon (3 different blends of carbon).

So I measure my water params last week with my new hanna alk, calc, and LR phosphate (not ultra low range) testers.

Ph has always been a bit low, 7.9 range. I cooked up some baking soda to make washing soda 2 weeks ago and added about 2 teaspoons over the last 2 weeks (a few ounces of a 20 ounce mixture every couple of days) to bring my alkalinity up a bit from the low end of range (to prepare for my first real attempt at sps type corals).

So 2 weeks ago (at roughly 8pm) we were at
Ph 7.88
Calc 441
Alk 7.65
Phosphate .41 (this is ppm, and high I understand)

Changed out my gfo, did a 20 percent water change, finished adding washing soda (finished last night) and tested again today at around 130pm.

Ph 8.07 (pretty solid. Will stay right around 8.02-8.03 at night, it's a little low because my skimmer has been off for 2 hours, need to dump it but I'm on crutches right now lol).
Calc 461
Alk 7.26
Phosphate (and I tested this twice because I don't believe it) 0.00

So is this plausible I've pulled all the phosphates out of my water (I also started dosing hydrogen peroxide 20 ml a day split 10 morning 10 night in the sump)?

Secondly, do I need to get more drastic to push my alkalinity up (I just want to be mid range, and I was hoping it would bring the ph up a bit with it)?

Third, would a drop in phosphates be a reason that I've got apparently more a available calcium without dosing anything?

Corals and everything are fed every 3 days, target fed probably an 1/8th to a 1/4 teaspoon worth of reef roids. They all look great, hammers/zoas/Duncan's growing like mad, all my sun coral polyps open every night, only coral showing and poor signs in a new goniopora which I just moved as it looked like he was getting too much light.

I have 4 tangs and an basslet for livestock and I feel like I am just pouring on the algea fertilizer by feeding them 2 to 3 times a day, but I have next to no algea in display (I've been swapping a rock here and there with the sump which has twice the amount of light intensity as the display) to give them a little bit to graze on.

 

[jsker]

What test kit are you using.

Are you testing nitrates?

I there any reason that you are running your Alk in the mid to lower 7's

Phosphate (and I tested this twice because I don't believe it) 0.00

for a system with that water volume you would have to run a lot of gfo to strip the system. I would say this would be human error with testing. I do it all the time and come back a two days later and check again.

 

[Jcald327]

I'm trying to bring the alk back up, which is why I've started dosing with washing soda (baked baking soda which apparently makes soda ash?). But I'm doing it rather slowly trying not to make any drastic changes. So 2 teaspoons of soda ash in a 500ml bottle of ro water, adding about 50 ml to my tank twice a day (I know I need a dosing pump). The system received a teaspoon of soda ash (over 5 days) after a 20 percent water change last week and my alk dropped that roughly .3 points.

As for phosphate kit, I'm using the low range hanna kit not the ultra low range so it reads in parts per million, not billion. I did a 3rd test, 10ml of tank water (even tasted to make sure I wasn't drawing from my RO cup for calc test), push button to zero meter, add reagent, shake for 2 minutes, place in meter and wait 3 minutes. 0.00 for the 3rd time.
2 cups of gfo powered by mj1200, running full blast then through 2 cups of carbon.
And just to reiterate I'm dosing 10ml of h2o2 in the am, and 10ml at bedtime.

I know this is not the ultra low level test kit so is it possible that between the fresh gfo, the h2o2, and what little algea I am growing in my refugium I'm just a net 0 on phosphate as it's all being consumed as it becomes available?

 

[Jcald327]

Just to add an additional note on the phosphates, I'm running kolar labs high capacity gfo which claims to be 4 times more efficient running almost a full reactor.