Hanna Phosphate Checker = Junk

[mtrcyclefish]

So let me start with a bit of background. A few years ago my tank was extremely successful. I had very good coral growth and color. Then I went on vacation and returned to a pump that had leaked, a top off system that had gone crazy, and a tank that looked, and smelled, like thick clam chowder. Needless to say it was a complete loss. I cleaned the rocks and restarted the system from scratch using the same rocks and sand. Since then no corals will grow or thrive in my tank. Everything will survive, but no growth, no color, no PE. Algae grows very well. The tank was moved almost 2 years ago and during that I replaced the sand and acid washed all of the rock. For about 3 months things were improved. Still very little growth and brown corals, but at least the algae issue seemed to subside. All during this time I was testing phosphate with a Hannah Phosphate checker and ALWAYS got a 0 reading. I even bought a calibration set for the Checker thinking that it was not working and it was spot on.*

As a bit of an experiment I bought some Lanthanum Chloride because I suspected that the tank had high phosphate. I put about 1 ml of LC into a liter of water and dripped a few drops into the tank. It looked like I had dripped a quart of milk into the tank.*

So here are my questions. Is it possible that my rocks became completely saturated with phosphate when my tank crashed and turned into clam chowder and have been leaching it back into my system for all these years? I know the Checker only tests for a certain type of phosphate so has it been missing this issue all along? I run GFO but could my system be so overwhelmed with phosphate that the GFO doesn't stand a chance? Will dripping the LC slowly over a couple of weeks help resolve the phosphate saturation issues?*

I should mention that I currently only have 4 fish and I feed very lightly. The tank is 115 gallons with about 60 in the sump. All other params are where they need to be.

 

[TheYellowSnow]

Algae grows on something. Even if you get a 0 reading you could have po4. All the checker is doing is telling you leftover po4.

Yes you rocks can absorb po4 and leech them back out.

Also a moved tank is a new tank.

If you see algae you have po4.
That's my method.

Use the checker to test if gfo is saturated.

 

[slief]

I said this in your first thread but since you started two threads on the same subject, I will reitterate what I said in your other thread.

First of all, the Hanna HI736 ULR Marine Phosphorus cheker is the one to get and is designed for ultra low level phosphorus testing in marine aquariums. There is a reason why the HI736 Phosphorus checker is noted a "Marine Checker" where as the HI713 Phosphate Checker you purchased isn't. The 713 phosphate checker will work but it's not as accurate will be be at least .04 off at ultra low levels (below .10) which kind of defeats it's purpose IMO. I've have seen this and compared test results between the 713 and the 736 multiple times. The 713 will read 0 Po4 at levels below .05 and in some cases, it will read 0 at even high levels. If you are seeing .04 Po4 on a HI713, I'd venture to say your actaul Po4 levels are closer to .08... The lower the levels of Po4, the less accurate the 713 will be. Especially below .10 Sadly, many people and dealers are misinformed and recommend the HI713 phosphate checker instead of the marine phosphorus checker. A quick look at the Hanna site and or a bit of homework yields this info. I've been using the HI736 Marine Phosphorus Checker now for years and have found it to be very consistent regent batch after regent batch.

That said, if you put LaCl in your water and it clouded it up, you really applied it seriously wrong and put your fish at risk. Especially if you have tangs. The precipitate impacts their gills and their ability to get enough o2 which isn't good and can kill the fish and anemones in a hurry. If it really turned as cloudy as you suggested, I am VERY surprised you didn't kill your fish.

Some bits of advice.. First, you should never dose LaCl directly into the water. You should only dose it into a 10 micron felt filter sock. You diluted into to RODI correctly but it should be dripped at a rate of no more than 1 drop per second. You will need to have spare 10 micron socks on hand because they will plug up and overflow as a result of the precipitate. Espcially in the presence of higher Po4 levels

I've been using LaCl for a number of years with good success and without issue. BUT.... When I use LaCl, I use an IV bag to manage the drip rate (1 drop per second) and 10 micron socks to capture and remove the precipitate. I take several hours to apply the contents of the 1 liter IV bag. I don't condone dosing into the skimmer as there are no guarantees that you will remove all the precipitate. I only recommend using 10 micron socks and making sure there is no water escaping out of them. All water needs to pass through the sock with the drip going directly into the sock. Also, if you start to see ANY clouding of the water, that is a 100% sure sign that you are applying it incorrectly and a sign that you should stop immediately before you damage or kill your livestock. If your water clouded the way you say it did, that is an absolute sign of severe overdosing and improper application method. When used properly, there should never be even the slightest sign of clouding because you are dosing slowly and capturing 100% of the precipitate before it gets anywhere near the fish.

LaCl is very serious stuff and I would strongly suggest that if you want to use it again, you read this thread in it's entirety. I would say your dose is correct but you method is flawed.
http://www.reefcentral.com/forums/showthread.php?t=1474839&highlight=lanthanum