De dierentuinen die het gebruiken doseren het net voor het zandfilter die zij veelvuldig gebruiken. Lanthanum choride reageerd met orthophasfaat en vomt ''vlokken'' welke mechanisch (10micron sok) of dmv een zandfilter verwijderd worden. Afschuimen schijnt niet optimaal te zijn.
Voordelen: goedkoop en goed werken middel.
NADELEN
Bij langdurig gebruik kan het neerslaan op glas.
Doktersvissen schijnen er gevoelig voor te zijn en kunnen er aan sterven.
Bij te snelle dosereningen kan er een witte mist onstaan wat neerslaat als
Lanthanum Carbonaat wat weer invloed heeft op de KH.
De juiste dosering is dus aanvolen!!
Hieronder nog een interessant citaat:
Lanthanum chloride heptahydrate has been used for many years by various private and commercial institutions here in the United States and abroad, to remove high levels of orthophosphates from fresh and brackish water systems (Disney World and Sea World of Orlando, Florida – information provided by request only), as well as the recreational pooland spa industry for over 20 years. Industry wide application rates have been denoted that lanthanum bonds to orthophosphate at a ratio of 1:1. Simply stated, it takes 1ppm lanthanum to remove 1ppm orthophosphate from water. As dry weight, this equates to 16 pounds of 35% lanthanum chloride heptahydrate to remove 1ppm orthophosphate (PO43) from 1-acre foot of water. This ionic attraction takes place within several seconds of contact of the lanthanum and the orthophosphate in both the water column and/or sediment. Lanthanum retains ionic bonding at pH levels between 5 and 11, making it highly useable in most water systems for orthophosphate reduction. The lanthanum acts as a flocculent, capturing the orthophosphate and settling to the lake or stream floor, or in recirculating system, being trapped for removal by mechanical filtration. Once bonded, it removes the orthophosphate from utilization by both microbial and algal species. Unless exposed to highly acidic or alkaline waters, the ionic bond will not release. As lanthanum has an ionic bonding level comparable to sodium, lanthanum will also bond and flocculate carbonate (CO3), arsenic, selenium, and chromium. Application rates can vary due to the presence of these other minerals. Lanthanum is widely used in Japan to remove both arsenic V and arsenic X from freshwater drinking supplies (Water Environment Research, Vol. 71, pp. 299-306,1999. S. Tokunaga, S. Yokoyama, and S.A. Wasay) meeting the Japanese Effluent and Drinking Water Standards, by treating at a 3:1 ratio of lanthanum to arsenic.
However, Randy thinks it may be better to use lanthanum carbonate. Lanthanum chloride is a soluble form, the carbonate is a mostly insoluble solid. Some of the media forms are this stuff. But, from what I found out long ago, when this was brought up ump-teen times, is that both may cause clouding of the water and increasing turbidity. The only big worry about Lanthanum is its toxicty..........we dont' known.
Also to add Lanthanum chloride dissociates in water and binds with phosphate to form Lanthanum phosphate, an insoluble salt. It may also produce some Lanthanum carbonate. So, keep an eye on Alk because it is seawater and not FW or a brackish system.
en nog een citaat:
I dilute it first in RO water and slow drip it into the intake of the sand filter.
IMO, that may be a much better way to use it than most people do, as you catch the solids on the sand filter and eventually export them. Many hobbyists are likely building up a layer of lanthanum carbonate sand on the bottom somewhere that has bound phosphate in it. Whether that is an issue or not I do not know, but I'd probably prefer to see it gone.
I've also not seen any data on the solubility limit of lanthanum in seawater. Lanthanum phosphate is very insoluble, but the carbonate and hydroxide may be less so, and presumably lanthanum is not at its solubility limit in normal seawater, so folks using it are boosting soluble lanthanum. Is that a concern? I do not know.
Lanthanum is known to impact the precipitation of calcium carbonate, for better or worse:
http://www.jstage.jst.go.jp/article/...ticle/-char/en
Cheers
Danny
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