4PPM Nitrate and GHA?

Johnson556 · Feb 1, 2019

My current tank has been running for almost a year, the rock and sand inside it about 2 1/2. It is a 180G display with a 50G sump, flow is 4 MP40's on reef crest 100%, and the tank is lit by six 80W t5's (bulbs are 8 months old) and 3 Kessil A360's. The tank has a filter sock, skimmer, and ATS. That is it, no GFO, no Carbon, no carbon dosing. Just 2-part via ESV B-Ionic.

For the first 3-4 months of the tank I had no detectable NO3/PO4 and my scrubber wouldn't produce anything other than slime, I started adding fish to get things moving and eventually got up to 2-4ppm nitrate around month 6, dino finally started to disappear. For the past 4 months NO3 has been stable at 4PPM but PO4 has been undetectable (Hanna). I dosed PO4 and accidentally shot it from 0.00 to 0.08, yeah, acros are still STN'ing and recovering...

I had this strange algae for the longest time but since my scrubber started taking off, and adding a black blenny, more than 90% of it has gone away. However, I am noticing patches of GHA now starting to appear. It was first a small amount on one or two rocks but now it is starting to appear elsewhere.

How is this happening with NO3 no greater than 4PPM and PO4 is "undetectable"? I have been cleaning my scrubber almost weekly due to the amount algae its producing, I would think this would out compete anything in the tank? Any Ideas?

ihavecrabs · Feb 1, 2019

IME having detectible PO4 and high Nitrate does not cause algae blooms by itself. My tank runs 15ppm NO3 and 0.04ppm PO4 and I do not have an algae issue.

When my tank first started, I had a similar experience to you though. Algae took over my display for a month or so while things were maturing and stabilizing. It sounds as if your has reduced significantly though.

My recommendation is to make sure you have herbivores in the aquarium and enough life to compete with the algae in the display (like your ATS). Keep harvesting half of your ATS regularly and not all at once. This will eliminate the downtime of the ATS as it kicks off growth again not allowing anything the opportunity to take hold in the display. Worst case, manual removal.

I personally still have algae in the rock crevices that get light but nothing can reach it. All my hermits and fish tend to hover around those areas awaiting their opportunity. All healthy reefs have algae :)

Johnson556 · Feb 1, 2019

Yeah, I could add some more CUC members for sure. Other than the hundreds if not thousands of Collonista snails that come out at night, I dont have too many snails/hermits.

My 5 tangs and blenny dont touch it...I think.

Ubergroover · Feb 1, 2019

Maybe you should try another test kit...I have had some test kits tell me PO4 is 0 and another tell me its 1. Look at what your tank is doing. GHA, there are nutrients. What test kit are you using? OR.....your fill water. I used to buy RODI from a LFS..or so I thought. The fresh water had .5 PO4...and I had GHA. anyhow if you have GHA and your test kit says your fine. Tank wins...try a different kit. just my .02

Vahanyos · Feb 1, 2019

It's possible it could be eating it up before you're able to test it in the water column - the nutrients I mean. I have some GHA in my display but it's very small here and there... it gets eaten and it spawns a tiny patch somewhere else and that also gets eaten, etc... I reduce feeding and nutrient import and it usually goes away. I suggest just reduce your nutrient import a little bit and it'll fade if the amount is too much for your liking.

I have a fuge with thriving chaeto and GHA in there as well, but it still shows a little in my DT

Johnson556 · Feb 2, 2019

Ubergroover said:
Maybe you should try another test kit...I have had some test kits tell me PO4 is 0 and another tell me its 1. Look at what your tank is doing. GHA, there are nutrients. What test kit are you using? OR.....your fill water. I used to buy RODI from a LFS..or so I thought. The fresh water had .5 PO4...and I had GHA. anyhow if you have GHA and your test kit says your fine. Tank wins...try a different kit. just my .02

I’ve had PO4 tested with 4 diff kits, all the same result. When I test st home I use hanna, Red Sea, and salifert for everything. Yes, three tests of each element usually. A little neurotic but oh well.

Vahanyos said:
It's possible it could be eating it up before you're able to test it in the water column - the nutrients I mean. I have some GHA in my display but it's very small here and there... it gets eaten and it spawns a tiny patch somewhere else and that also gets eaten, etc... I reduce feeding and nutrient import and it usually goes away. I suggest just reduce your nutrient import a little bit and it'll fade if the amount is too much for your liking.

I have a fuge with thriving chaeto and GHA in there as well, but it still shows a little in my DT

That’s what I have going on, just a few small patches here and there but I don’t want it to become a thing. Certainly not enough to make tests give false results. I want to remove a few fish that are complete butt-holes so I can drop for 3 cubes a day to 2...in a 200G....

What eats the GHA for you?

Vahanyos · Feb 2, 2019

A couple emerald crabs, and my starry blenny.

You’d be surprised how long fish will go without eating. You may see a very tiny bit of aggression (or you may not see a difference at all), but i would reduce to 2 cubes a day and you should see a difference after a few days.

That’s what I have going on, just a few small patches here and there but I don’t want it to become a thing. Certainly not enough to make tests give false results. I want to remove a few fish that are complete ***-holes so I can drop for 3 cubes a day to 2...in a 200G....

What eats the GHA for you?[/QUOTE]