Phosphate---root of many, many evils...and why my urchins wouldn't eat algae

[Sk8r]

What is phosphate? It's a very common presence in rock, in sand, in tapwater (which is why we use ro/di) and while it won't poison us---nothing but algae loves it. If you have hair algae you have way too much of it.

I happened to get an extraordinarily heavy load of it in some very nice-looking rock I got for a new tank: it's not evident until, of course, you get the hair algae mat that ate Chicago.

Now, of course, a phosphate test said I had some piffling amount. Of course it read like that: I also had pounds of hair algae---which accounted for what the test couldn't test. And until you can do for the algae---that phosphate ain't going nowhere. Finding something that EATS hair algae is also not easy. And of course once it does eat the algae it poos, and the phosphate laden poo goes right back into the water.

AND just to make matters crazier---the rock, she keeps on sending phosphate out into the water the minute you suck out the last phosphate that leached out. THAT won't be done until that rock has sent out its last phosphate and is now clean of it. It's like leaving dirty laundry in a bucket and cleaning it only by filtering the water in the bucket. But that's what we have to do. It's a slow process.

So...there are a few ways to get rid of phosphate from water: you can get other plants to take it up (a fuge) or you can bind the phosphate to something like a pad, or GFO, or whatever, so it can be removed.

And the more it takes out, the weaker the algae growth becomes.

I did get two little shortspine urchins (tripneustes gratilla is what F&S calls them, though I have some doubts) that just would not work. Would not eat. Nada.

Then I decided to get the largest possible GFO reactor (mine was the smaller) and charge it up to a heavy load (I have a 100 gallon tank) and let 'er rip. GFO works best in a fluidized bed, ie, when it's in gentle motion, with water all round the grains.

Now, the kicker: once I lowered the phosphate level with the massive GFO reactor---the urchins started eating like mad.

[stems]

Strange, thanks for the info. I had a small urchin from lfs that got rid of a small hair algae problem on the rocks but I also have 3 emerald crabs to help out too. Hopefully the algae won't come back again

[CoralReeForrest]

Originally Posted by Sk8r

What is phosphate? It's a very common presence in rock, in sand, in tapwater (which is why we use ro/di) and while it won't poison us---nothing but algae loves it. If you have hair algae you have way too much of it.

I happened to get an extraordinarily heavy load of it in some very nice-looking rock I got for a new tank: it's not evident until, of course, you get the hair algae mat that ate Chicago.

Now, of course, a phosphate test said I had some piffling amount. Of course it read like that: I also had pounds of hair algae---which accounted for what the test couldn't test. And until you can do for the algae---that phosphate ain't going nowhere. Finding something that EATS hair algae is also not easy. And of course once it does eat the algae it poos, and the phosphate laden poo goes right back into the water.

AND just to make matters crazier---the rock, she keeps on sending phosphate out into the water the minute you suck out the last phosphate that leached out. THAT won't be done until that rock has sent out its last phosphate and is now clean of it. It's like leaving dirty laundry in a bucket and cleaning it only by filtering the water in the bucket. But that's what we have to do. It's a slow process.

So...there are a few ways to get rid of phosphate from water: you can get other plants to take it up (a fuge) or you can bind the phosphate to something like a pad, or GFO, or whatever, so it can be removed.

And the more it takes out, the weaker the algae growth becomes.

I did get two little shortspine urchins (tripneustes gratilla is what F&S calls them, though I have some doubts) that just would not work. Would not eat. Nada.

Then I decided to get the largest possible GFO reactor (mine was the smaller) and charge it up to a heavy load (I have a 100 gallon tank) and let 'er rip. GFO works best in a fluidized bed, ie, when it's in gentle motion, with water all round the grains.

Now, the kicker: once I lowered the phosphate level with the massive GFO reactor---the urchins started eating like mad.

Question what was your phosphate level at in your tank before you got your GFO?

[snorvich]

Actually, that is a very interesting but strange story. I know that getting "base rock" can often bring phosphate with it so I have always avoided bringing it in if I could avoid it. Testing phosphate is not so easy to get a "real" reading even with a Hanna checker. But the urchins . . . why do you think that is true?

[Greg 45]

Sk8r I am going through the same issue
Mine started after several water changes system is over 1000 gal
Hair algae started and took over
Found that my ro/do tds 0 was putting 40 ppm of phosphate with each water change and top off water
Ordered new di for starters to strip all phosphate out of new water
Second step will be using SeaKlear phosphate remover it is cheaper and easier to use
There is a good article on RC lanthiumchloride

[droog]

Interesting! And of course very true...

I setup a new 120g tank at the beginning of the year. Nitrates are controlled at 0 (undetectable) and phosphats about 0.04ppm (Hanna checker ULR phosphorous checker). I've been dosing RedSea's NOPOX product from Day 1, and it seems to work well so far.

The live rock I got from the LFS seems to have been good quality. It even had some Coraline algae, and I'm getting more Coraline growth after only a couple of months (Alk never dropped below 8.5).

BUT my rock did come with some GHA which seems hard to get rid of. The power supply to my skimmer broke the week I went on vacation, so there was a MASSIVE growth of algae - presumably fed by the DOC. Fortunately the tank was empty/cycling at the time.

Now stocked with softies, LPS and 10 fish and CUC. Turbo snails are cleaning my glass, but don't touch the green fur on my rock. Tony (my yellow tang) is cleaning the rock near his favourite hang-outs, but its slow work. Maybe he'll be done a year from now!

I guess he's pooing the PO4 back into the water, but NOPOX (which I believe is a bacterial additive) coupled with good skimming seems to be keeping things under control. Call it a "Poo Export" strategy.

I have a small fugue growing algae on opposite cycle, but there is not much growth (my LFS can't get Chaeto), and from what I've read here algae growth is not terribly effective as a nutrient export strategy anyway.

-droog

[Sk8r]

Re the questions and the observation re the urchins: I do know that high phosphate levels will harm urchin reproduction. It may be that the level was so high it also affected their health, and killed their appetite. Tripneustes gratilla is a species that will eat about anything green, and eat it down to bare white limestone. But these little guys (caution: 1 tripneustes gratilla per 50 gallons! they grow large) were moving about without eating much of anything and never cleaning the rock. A few days after I put 3 jars of Phosban into their largest reactor and tuned it nicely---lo and behold, these little urchins began eating like mad, and white patches began appearing, which were their paths through the green jungle. I did put a note in the invert forum.

As for the level, I have a phosphate test and applied it to see if there was free phosphate (excess beyond what was in the algae) ---which was a yes. I can't remember the exact reading, and being an idiot, didn't write it in the log. In general, if you can read phosphate at all on an ordinary phosphate test, you're probably also looking at waving fields of green hair algae.

A note on the reactors: you need a pump balanced for the job; and having a pump powerful enough, and having a submersible (plastic valve) you can adjust lets you set the flow for the fluidized bed so that the bed just stays suspended in gentle motion. That's the most efficient. Putting phosban in a sack under your water flow will work, but nothing like what a reactor can do. I'd say the smaller reactor for a 50 gallon, and the larger one for a tank larger than that.

It's not a bad thing to have running early in your tank's life. If you start having a serious hair algae problem, forget halfway fixes: you can muddle along for months and lose specimens. Just get a reactor and be done with it. But expect with, say, the small reactor and a 50 gallon tank with a big, big hair algae growth, it's going to take 3 months to start making serious headway. It's not an overnight cure.

And as with most things, total removal is probably not good: if you have enough phosphate to keep your fuge algae growing and your copepods fed and happy, your tank will be healthy If you have no evident hair algae and your fuge is growing nicely, take the GFO reactor out of the system. Balance is the key in tank chemistry. Every element in its proper proportion. In the great ocean, over millions of years and with strong distributing currents, things get spread about: in your little tank, you have to intervene from time to time.