Considering a UV Sterilizer - opinions?

[xen]

Hallo all,

I'm considering buying a small UV steralizer for my planted juvenile discus tank.

I have some algae in my tank - mostly the fluffy, bearded stuff that seems to float around the tank and catch on leaves. I'm sorry, I don't know the name of it (but can post pics if that helps). It's a lot better than it used to be, but if a steralizer will slow it down, I'd be stoked :-)

I've read a fair bit about them, mostly good, but have also read some references to Cary saying they lower discus' resistance to sickness.

Have you guys had experience with UV units, either with planters, or juvenile discus? Any suggestions / thoughts / advice?

Many thanks again, guys!

Cheers,
John

[suisoman2]

UV steriliser is not really necessary in a planted tank, on the contrary:

Planted tanks generally need iron and trace element fertilisation, depending a bit on the energy input and growth speed of the plants ( especially if you have lots of light, heat CO2 etc... )
I assume you will be fertilising the tank with some commercial aquarium fertiliser or iron fertiliser. These fertilisers are generally chelated ( means the fertilising element is bound to a soluble element .This is done so that the iron or traces don't oxydise and precipitate out of the solution, and then the element becomes unusable for your plant. The energy of UV light can break the chelating bond and your fertilisers will become less efficient and if your tank is a fast growth high energy tank you will need to fertilise a lot if you don't want to run into plant trace element deficiencies. ( yellow plants with holes in it and stuff )

If you want to deal with algae there are better ways, UV will only help against green water, not against hair algae.
I advise you to learn on the aquatic plants mailing list , they can teach you how to get virtually no algae . ( basically: lots of plants,correct nutrient balance, low bioload , difficult with growing discus ) . Better to read the list there before asking questions. A question like, "how do I keep algae out of my tank" is too broad to answer, start reading up there, lots af professional advice.the ask for specifics.
http://fins.actwin.com/aquatic-plants/index.php


I had to fertilise 4 times as much when I had my UV on. ( especially Iron) .
The above is far less important when you have low light tank with low growth speed and not too many fast growing plants.

If your tank is balanced , healthy and not overfed you don't need UV at all.

YMMV :-*

suisoman Dirk

[xen]

Hallo Dirk,

Thanks for the advice - you seem to really know your chemistry (which I'm afraid I really don't!).

Currently I'm only giving my discus tank weekly doses of the Seachem Flourish range of ferts. I know they could use more, but 50% / day w.c. makes it very expensive business to keep dosing as much as I should (50% of the weekly amount after each w.c. by my reckoning). I figure that the plants that are doing well under these circumstances have been okay without much by way of ferts up until now, so I hope they'll continue that way.

I take your point about keeping a balanced tank. That said, this tank has always been about maintaining the discus' health before the plants'. I don't think my discus are overfed (although some of my friends would laugh heartilly at that). However, I'm sure a lot of the uneated food ends up trapped around dense plants where the discus can't reach it. I've found the hardest part of keeping this tank planted has been in cleaning around some of the denser growing plants (e.g. blue stricta).

I'll check out the aquatic plants list you mentioned - I sure have a heap still to learn about 'em :-)

Cheers!
John