how often/much water change? pls

[elliott]

very beginner question but i think i been neglecting my tank.. 250 gallons
2 pretty large royal plecs
20+ king tigers ranging in size
15+ breeding panda cories
5 neon teras

i use a pond filter built for 500 gallon but is a canister i added extra large sponges and it's ran with a 500gph pump
i also have two powerheads that are 300gph or so i believe, when clean they do push water to one side of tank to other

i started doing water changes weekly because i want my king tigers to spawn more, but i used to do it like monthly...
basically now i am keeping up and not letting the filters clog and run without the filter.
but how much water can i actually remove a week or so to keep everything safe, do people with pleco tanks remove 50%
of water a week or is that way too much? i'm trying to figure out if this can harm instead of help... any opinions i
would really appreciate, i am also feeding a lot more and starting to use carnivore waffers soon if that matters...

i really have no idea here, i know i been neglecting a tank because i had it for so many years and want to get it right now..

thanks fourm!

[FishnFins]

To me 50% a week sounds like a great starting point. In my experience I have found you don't need to worry how much water you change a day. A few of my colonies receive 40% water changes a day and I have good results.

[Barbie]

As long as changing your water doesn't cause some sort of fluctuation in the tank, you can change at least 50% weekly with absolutely no problem. You don't mention the temperature, but I guarantee that the Hypancistrus will condition much faster if the tank is warmed up. The problem with that will be the stress it causes on panda cories and neons.

Barbie

[elliott]

you guys were tons of help, thanks so much. i live in fl so the temp is always a little too high and water changes dont seem to drop it too much unfortunately its hard to keep it at 82 it seems to want to stay at 84 which i think is an issue, i will do the water changes and more air conditioning or cover up the sky light or at least half of it, it heats the tank up a lot during the summers...

[Shane]

Agree with everything said above. All my tanks get 50% weekly water changes. I would comment that a 500 gph filter on a 250 seems quite under strength. On my 125, for example, I am running a 925 gph pump to the canister plus a 1,250 gph powerhead and that is for a low stock community tank.

My loricariid specific tanks get far more turnover. A typical 40 gallon set up for plecos in my fishroom has a 400 gph Emporer filter plus two 145 gph Marineland powerheads attached to sponge filters. Expressed another way, that equates to almost 200 gph more turnover on a 40 gallon tank than you are using on a 250.

As resources allow I would start adding much more turnover than you currently have.
-Shane

[catfishchaos]

I used to do 25 percent water changes when it was just my 30 or so dither fish but once I got my clowns I had to start doing 50 percent water changes (holy crap to put it mildly) And now that my fish tank has 7 L134 in it I still do 50 percent water changes because i don't find them that dirty. Like others have warned the cories may be more vulnerable to temperature changes.

[David R]

First and most obvious question (can't believe no one has asked!), what are your nitrates before and after doing a water change? They are the primary reason to change water, and if you're maintaining them with 30% water changes and your fish are healthy and breeding I would see no reason to go to 50%+ changes. Large changes can be great for your fish, but as Barbie mentioned they can also cause more stress than is necessary if they lead to big fluctuations in temperature or other parameters.

I agree that a 500gph pond filter seems inadequate for a 250g tank, although yours doesn't sound too heavily stocked, but the results of your water tests will speak for themselves. If you're not reading any ammonia and you're happy with the clarity of the water then you obviously have enough filtration.




disclaimer, yes I know there are all sorts of other non-testable things also removed by water changes, but IMO nitrates are still the first indication of whether you're changing enough water.

[craig09]

I water change every other day just 2 buckets out which is 30ltrs in total but that is down to my OCD clean fish tank, but also depends how heavy i feed to try and get my plecos spawning. If im feeding heavy water changes can be daily again 2 buckets

[Nabobmob1]

I truly believe one cannot change too much water. Yes I'm sure their are exceptions for instance fish that come from stagnant waters. I change all my tanks 50-60% twice weekly or more depending on stock levels and feedings.

[Barbie]

I agree that you can't change too much water, at least here locally. I've been places that you CAN due to chloramines or fluctuating dissolved gasses. Here, I am blessed with water that allows me to change 90% of the water in tanks with Ancistrus fry and it doesn't stress them and they grow like wildfire. I do not use nitrates as an indicator of the need to change water because I have them in my tap water 5-10ppm and because even at 20ppm, if plants or too much driftwood, I can easily crash the 3 degrees of kH that is all we have for buffer. Big changes keep everything stable and the fish happy and breeding. It just depends on your local water supply though.

Barbie