Phosphates stuck at .1

Mwhitedesigns · Jan 16, 2019

GM class,
I have a 5 gallon spec v with some upgrades.

upgraded to Cobalt Aquatics MJ606 return pump
In tank media running
- filter floss
- chemi-pure blue (recently swithched from elite with the hopes of reducing even more phosphates)
- purigen
Marine Orbit IC

I am having a GHA issue and my phosphates have been stuck at .1 for about a week and a half. Testing using the new HI 774 LR Hanna Checker. My tank is 3.5 months old. I realize that algae is common in younger tanks. My params are as follows.

78 temp
8.1 PH
0 Ammonia
0 Nitrites
5-10 Nitrates
.1 Phosphates

I do weekly water changes of about 30-35%. I use a turkey baster to blast of rocks, corals etc. and the very top of my sand bed every water change. However my phosphates are always at .1!!!

I feed freeze dried mysis once a day. They finish it all in about 3 minutes. So I find it hard believe that over feeding is an issue.

I haven't tried brushing off the GHA with a brush yet as I have multiple corals on stacked rocks and didn't want to remove and disassemble them yet. I tried pulled it off with tweezers but the roots are too long at the moment and it does not come off easily.

Everything is growing and is happy (including the dang GHA!!!!). Any thoughts on what to do to bring down the phosphates even more? From what I've read the Chemi-Pure Blue should be plenty for this sized tank. I thought about Phosphate RX however it looks like it shouldn't be used on tanks smaller than 10 gallons.

EmdeReef · Jan 16, 2019

What kind of rocks did you use and has it been cured? Water changes are usually not the best way to export phosphates.

Mwhitedesigns · Jan 16, 2019

I used mostly dry rock. I got one piece from the LFS that was "cured" I guess. It was in a tub with a bunch of other rocks in circulated SW.

EmdeReef · Jan 16, 2019

What kind of corals? You could use a small dose of LaCl just dilute it with a lot of RODI and divide in small doses over a few days. Could for example add to your top off water.

Alternatively, running GFO or aluminum based phosphate remover will work given the size of the tank but you may have to replace it a few times initially.

Mwhitedesigns · Jan 16, 2019

I currently have a colony of Zoa's (probably about 20 heads), Neon Green Montipora Digitata, Grape Cristata and a Pipe Organ. Additionally I have a RBTA. Lastly, I have some Red Grape Macro and some Red Bush Macro in my display.

SPR1968 · Jan 16, 2019

You could try adding some GFO in a bag in that size tank, I use rhowaphos, but maybe just take it slowly so the level reduces at a slow rate in case your corals have been used to the high levels. And it will need frequent changes to start with as it becomes depleted

You might have some phosphate tied up in the rockwork which needs to leach out and maybe that’s why water changes aren’t having much effect.

I think the chemipure blue is a form of carbon rather than for reducing phosphate from what I’ve just read about it

Mwhitedesigns · Jan 16, 2019

I was using Chemi-Pure elite. That supposedly contains GFO right? Would it be worth switching back? Or would you just add some GFO in a bag and leave it as is.

SPR1968 · Jan 16, 2019

Mwhitedesigns said:
I was using Chemi-Pure elite. That supposedly contains GFO right? Would it be worth switching back? Or would you just add some GFO in a bag and leave it as is.

Yes although I’ve never used it, it looks like the Elite is the one to remove phosphate, but you can still continue with the Blue as that’s to remove other organics

I’ve always used rhowaphos but that’s just me and rhowaphos certainly works if you can get it.

Yes, just add some in a bag and see how you get on. But remember it may need changing frequently to start as it becomes spent as it absorbs the phosphate

Mwhitedesigns · Jan 16, 2019

Thanks for chiming in. I will grab some and place in a bag and throw it in my media basket. I see alot of reviews saying the particles are very fine. Have you had an issue with that? Would you double back in to try to keep everything in?

SPR1968 · Jan 16, 2019

Mwhitedesigns said:
Thanks for chiming in. I will grab some and place in a bag and throw it in my media basket. I see alot of reviews saying the particles are very fine. Have you had an issue with that? Would you double back in to try to keep everything in?

If you mean rhowaphos, yes it is reasonably fine and needs rinsing in RO before you add it to the tank.

You just want a mesh bag with fine mesh and that should be fine. I would put the rhowaphos in the bag, then drop the bag in RO and just ‘dunk it’ a bit to get the fines out. This will also make sure the mesh is fine enough to contain the rhowaphos before you drop it in the tank.

Just start with a little and then alter the amount until you get the desired effect, a slow reduction.

Mwhitedesigns · Jan 16, 2019

Thanks man. Appreciate all the help.

jda · Jan 16, 2019

The sand and rock bind phosphates, or had them bound when you purchased them. When you lower the concentration in the water with GFO or LC, the rock/sand releases some to bring the equilibrium back up, but the equilibrium is just barely lower than last time. It can take a lot of GFO or LC to keep lowering the water where the concentration gets lower, but if you keep after it, it will go down.

The GHA will form on the rocks near the phospahte source. The dry rock out keep on releasing phosphate for a year or two, so keep fighting it.

Daniel91 · Jan 16, 2019

What’s the TDS of your RO/DI water source? If you get it from your LFS, have them test it in front of you.

It is quite common that people disregard the impact on phos from higher tds water.

Mwhitedesigns · Jan 16, 2019

I am not sure of the TDS. I actually need to re-up soon so I will ask them when I got to my LFS.

Daniel91 · Jan 16, 2019

Be sure they test it though - in front of you. They might not even know if their RO/DI unit needs some filters replaced

Mwhitedesigns · Jan 16, 2019

Will do. I actually had an issue recently where I failed to test my RO/DI prior to my WC. I had been getting it from this store on and off. I completed a water change and decided to take a ammonia reading and it was between .5 and 1 PPM. I dosed some Seachem Prime to help neutralize it and went to the store to ask. Sure enough, their RO/DI was coming at .5 PPM as well. They looked at me like they had no clue why or what to do. I was pretty astonished. I went back about a week later for something completely different and asked if they had resolved their issue. They hadn't and they said they still didn't know why ammonia was showing in their water. Needless to say, I will never purchase water from them again.