Dosing LaCl in ATO

[Pyrosteve]

I’m having phosphate issues and burning thru GFO about every 10 days. Phosphate hits 1ppm and algae blooms. I replaced my RO membrane so I’m thinking the PO4 is coming from my rock. Not sure if leeching is possible but it was in a FW tank for a few years using tap water (I did soak/rinse in RO water before adding).

At any rate I’m thinking of dosing lanthanum chloride (phosphateE) from my ATO. The tank is only a few months old and I’d really like to keep algae under control while it matures. What’s a good starting point? My tank is about 30g with a 7g ato res that lasts almost a month. I know a little goes a long way. 1ml reduces 4g 1ppm. My thought was to ad 1/2 dose (4ml) to the ATO per refill at the start and test from there. Any advice on using it?

 

[jim_fitz]

never heard it done that way before
i understand that with phosphate removal there needs to be a 'mechanical' process following the introduction of the LaCl
which is normally done by dosing into a sock or directly into a skimmer

if you added direct to your ATU depending upon the quality of your water in my precipitate and then re-release (bit of speculation there)

 

[csb123]

I think it would work just fine. I’m looking into a doser to continuously add LaCl in tiny amounts to maintain a stable, but low level.

 

[clm65]

If I understand correctly, you are going to dose 4ml over a month? If so, I don’t think that will be enough. I’m not sure how much GFO you are using, but since you are going through it in 10 days and hitting 1 ppm PO4, I’d assume you have quite a bit of phosphate stored in your rocks. I would start dosing it the normal way (mix with RO/DI water in a gallon container and drip into a 10 micron sock or into the skimmer inlet) and see how long PO4 takes to return. Then you can calculate the rate that PO4 is leaching out and determine an offsetting LaCl dose for your ATO. That’s my thought anyway. I haven’t done it that way, so it’s just a guess on my part.

 

[philosophile]

Wait... your tank is only a few months old?

Have you done a water change or two to see if that clears it all up? Is your rock fully cycled? Have you ever just taken it out and swished it in a bucket of water that you were going to toss out, from a water change?

Are you feeding? How much? What’s in your tank?

 

[Pyrosteve]

never heard it done that way before
i understand that with phosphate removal there needs to be a 'mechanical' process following the introduction of the LaCl
which is normally done by dosing into a sock or directly into a skimmer

if you added direct to your ATU depending upon the quality of your water in my precipitate and then re-release (bit of speculation there)

From what I understand, the more it's diluted the less precipitation? It's why I was thinking to use my ATO with the added water volume. Hoping my skimmer can pull out any that does occur.

I think it would work just fine. I’m looking into a doser to continuously add LaCl in tiny amounts to maintain a stable, but low level.

I was thinking this also I just don't have a dosing head available and can't fit another at the moment.

If I understand correctly, you are going to dose 4ml over a month? If so, I don’t think that will be enough. I’m not sure how much GFO you are using, but since you are going through it in 10 days and hitting 1 ppm PO4, I’d assume you have quite a bit of phosphate stored in your rocks. I would start dosing it the normal way (mix with RO/DI water in a gallon container and drip into a 10 micron sock or into the skimmer inlet) and see how long PO4 takes to return. Then you can calculate the rate that PO4 is leaching out and determine an offsetting LaCl dose for your ATO. That’s my thought anyway. I haven’t done it that way, so it’s just a guess on my part.

This is where I was having trouble. Figuring out how much and how fast. I think you're right, I need to find out how much PO4 is building up in X amount of time to determine dosage. Thanks.

Wait... your tank is only a few months old?

Have you done a water change or two to see if that clears it all up? Is your rock fully cycled? Have you ever just taken it out and swished it in a bucket of water that you were going to toss out, from a water change?

Are you feeding? How much? What’s in your tank?

Yes. I've done a couple of WCs and it knocks the levels down slightly but they return. The rock is dead live rock I've had for about 15 years. It was in a FW tank for a few years. I removed it and let it soak in RO/DI for about a month. Was that not long enough?

I am feeding on the heavy side. I've got 4 cardinalfish (plus a pair of clowns) and there's less aggression when I feed them a few (3) times a day.

 

[philosophile]

Yes. I've done a couple of WCs and it knocks the levels down slightly but they return. The rock is dead live rock I've had for about 15 years. It was in a FW tank for a few years. I removed it and let it soak in RO/DI for about a month. Was that not long enough?

Just soak? no that isn't going to do anything. you need to get bacteria to metabolize the phosphate, and other dead stuff in there, then remove the bacteria. usually what people do is put it in salt water, let bacteria build up, then aggressively dunk and swish the rock in a bucket of SW, then change buckets, and keep doing that until the water is mostly clear.... then wait another week, repeat swishing, etc. it's called cooking live rock.

Also feeding three times a day is A LOT. they had either be tiny pinches, or you better have an amazing filtration system, or you're doing water changes a lot and often. the general rule is dont feed more than a fish's eyeball to a fish in a day, with some fish being big exceptions like mandarins.

So... what to do about the rock? I know you said you can't take it out, but however inconvenient it is, I think you need to take it out and work your next water change, really dunk and swish your rocks and see the kind of gunk you get out of them. then scrub it with a toothbrush to get the algae off, and rinse again with SW, and back in the tank.

Cut back on feeding. add some kind of phosphate removal media like GFO, and then your skimmer up so that it produces a fairly wet skimmate, to help with the organics being produced by all the fish poop. I would also probably vacuum 1/3 of your substrate, and then another 1/3 in two weeks, and another 1/3 two weeks after that. dont do it all at once. most people dont vacuum their substrate often if ever, but in your case, I think it would help.

If you use GFO, go slowly and reduce phosphate over a period of weeks. sudden phosphate removal can shock some corals. Also get a filter sock and put what comes out of the gfo reactor through the sock, in case GFO gets ground up into dust.

 

[Pyrosteve]

Just soak? no that isn't going to do anything. you need to get bacteria to metabolize the phosphate, and other dead stuff in there, then remove the bacteria. usually what people do is put it in salt water, let bacteria build up, then aggressively dunk and swish the rock in a bucket of SW, then change buckets, and keep doing that until the water is mostly clear.... then wait another week, repeat swishing, etc. it's called cooking live rock.

Also feeding three times a day is A LOT. they had either be tiny pinches, or you better have an amazing filtration system, or you're doing water changes a lot and often. the general rule is dont feed more than a fish's eyeball to a fish in a day, with some fish being big exceptions like mandarins.

So... what to do about the rock? I know you said you can't take it out, but however inconvenient it is, I think you need to take it out and work your next water change, really dunk and swish your rocks and see the kind of gunk you get out of them. then scrub it with a toothbrush to get the algae off, and rinse again with SW, and back in the tank.

Cut back on feeding. add some kind of phosphate removal media like GFO, and then your skimmer up so that it produces a fairly wet skimmate, to help with the organics being produced by all the fish poop. I would also probably vacuum 1/3 of your substrate, and then another 1/3 in two weeks, and another 1/3 two weeks after that. dont do it all at once. most people dont vacuum their substrate often if ever, but in your case, I think it would help.

If you use GFO, go slowly and reduce phosphate over a period of weeks. sudden phosphate removal can shock some corals. Also get a filter sock and put what comes out of the gfo reactor through the sock, in case GFO gets ground up into dust.

Well I cut back on the feeding to a pinch of flake and 1/2 cube of mysis (no more pellets). I also vacuumed the substrate and added lg nassarius snails. I forgot to mention that I did put the rock in a bleach solution and let it sit in the sun before soaking in the RO/DI water. I added new GFO 11 days ago and PO4 levels are still near undetectable so hopefully that was it.

I still ordered some PhosBan L (LaCl). I'm going to try and use it in my ATO in very small amounts and run the GFO only if I get a spike. To me it seems like a better way to keep phosphate stable instead of the up and down of GFO.