Hanna checker totally off?

[BaileyB]

I’m using the Phosphate ULR 774 to test phosphates because sadly, I’m not one to test often. But my Hanna checker is testing my water level at .9?! This can’t be right? Could it? I have about 80 frags ranging from acro to Goni to zoas, and all seems well.. wouldn’t things start to go crazy at that level? Recently used Reef Flux (anti fungal medication safe for reef tanks used to get rid of some pest algea I introduced into the tank) about 2 weeks ago, could this be the cause of my high phosphate? And I’m assuming I should do a large water change? How large? My system in total is about 80 gallons

 

[W1ngz]

Try a dilution test. Mix say 1 cup of tank water with 2 cups of freshly mixed water. Test the mix. That should put you around .3 if everything is working correctly.

Lots of dead dissolved algae could easily mean lots of phosphate and nitrate.

0.9 is the max though on the 774 so you might want to check it with something else.

 

[nereefpat]

How old is the tank? What rock did you start with? Nitrates?

Water changes don't work very well for phosphate, since rock and sand absorb and release phosphate from and to the water.

If corals look fine, and you don't have terrible algae issues, then I wouldn't drastically change anything.

 

[hllb]

Oh yes, reef flux drove my po4 to almost triple what it was - even though it didn’t kill the algae LOL

 

[ingchr1]

Did you run a second test to validate the reading?

You could also check the checker with the Hanna standard, or another test kit.

 

[BaileyB]

That’s a great idea, I’m goi

Try a dilution test. Mix say 1 cup of tank water with 2 cups of freshly mixed water. Test the mix. That should put you around .3 if everything is working correctly.

Lots of dead dissolved algae could easily mean lots of phosphate and nitrate.

0.9 is the max though on the 774 so you might want to check it with something else.

Great idea, I’m going to give that a try and see if it reeds .3 or close to it! I’ll let you guys know what it reads

 

[BaileyB]

Did you run a second test to validate the reading?

You could also check the checker with the Hanna standard, or another test kit.

Yes I did, both read .9

 

[BaileyB]

Oh yes, reef flux drove my po4 to almost triple what it was - even though it didn’t kill the algae LOL

Luckily mine made my tank look brand new! All the algea melted it was amazing

 

[BaileyB]

How old is the tank? What rock did you start with? Nitrates?

Water changes don't work very well for phosphate, since rock and sand absorb and release phosphate from and to the water.

If corals look fine, and you don't have terrible algae issues, then I wouldn't drastically change anything.

Dry rock to start, and set up is coming on 2 years now in a couple of months. Nitrates are less than 5 ppm. And the product I used said to do a 30% water change 3 weeks after use.. 2 weeks in I’m thinking I’m going to do the recommend water change now

 

[nereefpat]

Aha. You killed the algae, and now you're left with the phosphate.

GFO would work better than water changes. Like I said, water changes aren't great for dealing with phosphates.

 

[BaileyB]

Aha. You killed the algae, and now you're left with the phosphate.

GFO would work better than water changes. Like I said, water changes aren't great for dealing with phosphates.

I did a test with 1 cup of tank water and 2 cups of fresh mixed salt water and Hanna checker read .44 .... so I plan on changing more water like medication instructed but don’t want to buy GFO since I don’t know much about it, my fuge is full of chaeto right now, will it absorb phosphates down to a safe level with a substantial water change (35-40%) or do I NEED to run GFO? and could I just toss it in the sump instead of running a reactor?

 

[W1ngz]

That tester maxes at 0.9 so you probably have more in the range of 3*0.44= 1.32

A 40% water change will knock it down, but it's also been bound up in the rocks by now, so expect it to climb again pretty quick. Do a bigger change if you can, or plan a second soon.

Allowing the chaeto to work on the phosphates could result in depleted nitrate which you don't want either. GFO will target the phosphate specifically.

GFO cannot simply be dumped anywhere, it needs to be contained so you can remove it when the time comes. It's most efficient in a reactor with low flow through it.

 

[X-37B]

Use phosgaurd in mesh bag and monitor daily. It will drive po4 down quick so use a small amount.
When po4 levels are where you want just remove and monitor. Works well.
Get a standard to check your unit. Hanna sells them.

 

[Malifry97]

My Take: I know it seems like extra work, but I would use GFO or the likes, it strips phosphate way too quick and will more than likely irritate your acros and other corals. I would dose nitrate, and allow your chaeto to do its job. This will prevent the problem of driving down the nitrates with the phosphate. Just dose the nitrates to 5 everyday and let the chaeto do its work. That’s my opinion on the matter and is exactly what I would do in this situation.

 

[PatW]

Once every so often, my Hanna ULR phosphorous checker gives me a crazy high reading. On a second try, I get a number that is in line with the trend. As a guess, I think I get a bit of particulate with high phosphate.

 

[sde1500]

I did a test with 1 cup of tank water and 2 cups of fresh mixed salt water and Hanna checker read .44 .... so I plan on changing more water like medication instructed but don’t want to buy GFO since I don’t know much about it, my fuge is full of chaeto right now, will it absorb phosphates down to a safe level with a substantial water change (35-40%) or do I NEED to run GFO? and could I just toss it in the sump instead of running a reactor?

I would use GFO, you released a lot fast, it is good at removing a lot fast. Curious why you feel comfortable using an anti-fungal med that happens to kill algae, but not use a product specifically for phosphate removal?

 

[C. Eymann]

Id recommend GFO in this case as well but take care in the amount you use, less is always better than too much with GFO.

Use that to drop it down to .3/.2. then Id remove the GFO and let it fall gradually the rest of the way into your preferred range.


Just my .02