Are Large Water Changes Killing Fish? Small vs Large Water Changes -

[pops]

never killed any of my fish. always 90% or fin level.

 

[Chockful O Phail]

Regarding heavy metals from HW tanks ............

My cold supply line drops down into the 40's for much of the year, which kind of rules out just using the cold supply only with 80+% water changes. Never once had any issues mixing hot/cold lines to refill my tanks, even with 10-20 year old hot water tanks. Most of those exact same heavy metals are found in the parts per billion range in local rivers and lakes. For those concerned one can flush/drain their tanks once or twice a year to remove any potential build up. I personally don't believe even that is required, but it can add some years of life to your HW tank.

This is what got me, sure cold would work in a temperate climate but sub 50 full water change would definitely do more harm than good. During the winter here in IA I have to space out the changes so the water heater can keep up.

 

[tarheel96]

ive had more fish die after large water changes than for any other reason. must be something in my tap water around here. i do about 30% weekly changes now which works well.

I know there are people with you experience and that's part of the reason I started this thread. I understand things are working out well for you with weekly 30% changes and I'm glad you've got that worked out. There might not be anything that can be done in your case ... I don't really know at this point.

But I'd really like to hear more about your situation so I and others can get a better understanding of why that's been happening. There are only maybe 2 or 3 common causes and it should be easy to figure out the likely culprit.

Do you know if your water is soft or hard? If not, what about your tank's pH?

 

[souzie]

Yay for large WCs!!!

 

[MrsE88]

I'm also part of the big/fin level wc. I do them 2x a week. This gives me wiggle room if something comes up and all of a sudden I miss a wc for a few days.

 

[Chockful O Phail]

Yay for large WCs!!!

View attachment 1281358

Sorry for the slight derail, but holy cow those RBP are huge!

 

[souzie]

Sorry for the slight derail, but holy cow those RBP are huge!

Haha...

 

[jaws7777]

My limiting factor is my pearsei. Hes gotten soo big that im not abke to really drop the level to wear i used too. I feel like since we're already spending time changing water why not just go fin level.

RD spoke about this somewhere but not only are we removing nitrates but other things like hormones or what ever. Regardless if my nitrate level the fish always look there best after large wc's. This plus dosing with a probiotic (ridx) i havent had to deal with sick fish for a few yrs now

 

[shookONES]

I'm a fan of huge water changes. I do 50-75% twice weekly in my comm tank, and a single 50-75% in my other tanks religiously. When it comes to water changes, it seems everyone is obsessed with nutrient export (removing nitrates and whatnot), but the other side of the coin should also be addressed. Fish consume a number of trace elements from the water column itself. In our often overstocked aquariums, these trace elements get depleted rapidly. I see a lot of threads that promote rare water changes and quasi "self-sustaining" setups, and they're frankly dumb.

Don't believe me? Talk to someone who runs a heavy 24/7 drip. I've never seen fish grow so rapidly as a growout in one of these tanks. A few years ago, I had some growouts (zebrina, mahseer, dats) stashed at a friend's house. His setups were all on a drip and after a month or two, I couldn't believe my eyes. The fish grew like weeds.

 

[RD.]

Anyone that has raised fry or young juvies soon learns that the key to rapid growth is to throw as much clean water at those young fish as possible. 50% or more per day is not too much. This is precisely why I posted those discus videos. They aren't doing massive water changes like that in a commercial facility for funsies.