Nitrates and Plants

[darkdep]

I've been feeling guilty the last couple days...work on my new tank stand, lots of house projects this week, and as such my "main" 30gal tank hasn't had a waterchange in over 2 weeks.  So, tonight I decided to do a nitrate test, assuming it would be off the scale (I've noticed an increase in algae growth).  To my surprise, it was only 10.

This tank has a lot of plants in it (I wouldn't call it "heavily planted", but there is a large amazon sword, 4ish bunches of hygro, a couple Vals, a small crypt, and something else I got before I knew what I was doing and therefore I can't ID.

Now I'm wondering...OTHER than for topping up from evaporation, and nitrate removal, is there any other "reason" for waterchanges?  (Ignoring for a moment the fact that waterchanges are a good excuse for vacuuming the gravel)...?

[luvfishies]

Yes, removal of things we can't test for, and adding back trace minerals/elements.

[discusFans]

in a planted tank, if it is well balance between fish load and plants, it is possible to keep water change to a lesser fequence, depending on the kind of fish you have of course. And assuming u have regularly added some nutrients such as trace elements..

[kennyman]

Disolved Organic Compounds (DOC's) I hear a bit about them over at badmans. There are a couple of people there who have some heavy biology background and they explain it good every once and a while for us noobs.

Although its basicly like luvfish says . . .  stuff  

[edit] http://www.badmanstropicalfish.com/message_board/messages/16/39085.html
About halfway down youll find a post by Dan. There is a bit of info there.

[darkdep]

Interesting stuff.  I've got some more reading to do...this concept is more in favour of large water changes, which is almost the opposite of some other things I've read.

[kennyman]

50% per week is what you will find recomended on that site religiously. I can't quite keep up with that much as Its just too many buckets for me. If I had to treat for chlorine I bet I'd be doing even smaller changes than the 16g/week I do in my 55g mbuna tank. (4 buckets) No python for me. My tank is 30' from my kitchen

I think its most important to do water changes often than how much though. doing 50% or more once a month is just asking for trouble. The levels of DOC's will be up and down like a yo-yo.

[BigDaddy]

I do 50 per cent waterchanges per week simply because I have a planted tank.  50 percent water changes weekly, coupled with my weekly fert schedule, means in a worst case scenario, I can only have double whatever I am dosing into the water column at any given point in time.

[Marx]

i have never done a 50% water change on any of the big tanks i've owned..

i do about 10-15% a week.. I follow DR fosters recommendations, small weekly water changes with the addtion of trace elements/ferts as required.

I have to say that i know people with aquariums that have been in this hobby alot longer then i who do water changes once a month.. and not to big at that.. 25% even less.. and have successful tanks..


my tank is 125g and half(62.5gal) of that is a lot of water per week lol..

but to tell ya the python really helps..

Plus my Reef tank uses  about 1.5" of top up water a day.. on top of that i do 7.5gal water changes every weekend. of RO/DI water

so the waste water is like 4 to 1 ratio.. which is a big waste of water..

but Like i said before could my tanks use more sure.. but do i think they need more nah..

[squeeker]

I do 40% weekly on my tanks.  Those messy goldfish really need it!

[BigDaddy]

With planted tanks, especially high growth planted tanks where you need to administer a lot of ferts, 50% weekly is common.

Read up on Tom Barr's Estimative Index for further reading...

[kennyman]

I had the pleasure of attending an IRC chat with Tom Barr as the guest speaker. When I finaly understood the EI thing he was pitching it was like "Man that is such a logical idea, why didnt  people always do this"?

If anyone looks around on the forums I listed above they will find a link to that chat.

http://www.badmanstropicalfish.com/stories/chat/chat_main_2005.html

[PaleoFishGirl]

Although a 50% weekly water change might be ideal, let's face it - for many of us this isn't practical! Don't be disheartened, though - with careful monitoring you can get away with a much less severe regiment of water changing.  20% per week can be more than enough, especially when your tank is nowhere near a water source.

On a sadder note, my mother doesn't perform water changes nearly often enough, only tops up the tank when it evaporates too much.  Maybe she changes 50% every few months!! She lives in AB so I don't get home often enough, but needless to say when I do I shell out for water (their water comes from a mineral-rich well that is very poor for keeping fish; they have to buy bottled water to drink as well as to change the tank water).  She's got angels, corys, hatchets and a betta in the tank and somehow all are doing well, in case you are concerned

[rockgarden]

I tend to belong to the "don't fix it if it ain't broke" school of thought.

In my 65 gallon, the only water changes that I do are to replace evaporation and to replace the bags of water that go to the OVAS mini-auctions each month.

PS.  More bags of java moss, etc. coming to Monday's OVAS.

For those who fertilize heavily, water changes make sense.

To those who live in areas with naturally hard tap water, water changes might make sense depending on what pH and hardness you want in your tanks.

Ron

[kennyman]

One thing we kind of over looked here is the role carbon and other chemical filtration media play. The idea behind large regular water changes is an alternative to chemical filtration. People I know doing half a tank per week do not use chemical filtration components. The only filter media they use is foam, ceramic and biowheels.

[darkdep]

Well, that's me.  I don't use Carbon.  But Carbon has no effect on Nitrates anyway.

[BigDaddy]

One thing we kind of over looked here is the role carbon and other chemical filtration media play. The idea behind large regular water changes is an alternative to chemical filtration. People I know doing half a tank per week do not use chemical filtration components. The only filter media they use is foam, ceramic and biowheels.

Chemical media costs $$$.  Water changes are free.

[Aiglos]

Water changes cost $$$.

Think about the water conditioner you have to use, I go through alot of water conditioner.

[darkdep]

Water conditioner is cheaper than Carbon.