Water changes how much and how often for plecos

Pete

Member
May 19, 2009
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North wales
Hi everyone its an old topic I know but I've been thinking about the water changes I do and wondering if I'm changing too much

Is changing 40% of the water at once (weekly)too much ?

The tanks are rio 400's planted and have 2 externals and 2 internal filters each
One tank is reasonably stocked with 5 plecos including 2 Royals and tetras barbs ect the other's only got 2 plecs as one of them a Royal is a right grumpy begger

At the mo I change 40% weekly but was reading on another site that more than 20% at once is too much
Nitrates are at 10% on a Dr wellfish test kit but I'm going to get another test kit as that seems low
I will try doing 10% twice weekly and see how it goes
Pete
 

matubula

Retired Staff
May 7, 2009
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Chester, UK
For ages I used to change 50% week and it didnt seem to have any negative effects but when I can I change 25% twice a week, just so it fits in with feeding veg so I can hoover the poo. I dont know what effects it has chemically on the water.
 

Tony_s

Member
May 4, 2009
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Wisconsin
I do about 10 to 15 % daily and clean the gravel every other week.

Fresh water means more Oxygen which means a healthy tank.

Some betta keepers change water every day.

If you're not losing fish,Why change your schedule??
 

2wheelsx2

Member
Dec 21, 2009
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Burnaby, BC, Canada
Fresh water from the tap is supersaturated with CO2 because they usually put in carbonates to prevent corrosion. That's why if you're adding water straight from the tap to the tank, you should splash it around a bit to dissipate the excess gas. It will also help add O2 to the water. If you hold the outlet underwater to prevent splashing, then the excess gas will degas underwater, which might cause a gas problem with your fish (gas bubble disease).

As for the water change, I do 50 - 60% waterchanges every week, even in my 125 gallon. If the tank is looking dirty because I've neglected it for a week because of travel, I will do 2x50% water changes for a week or two to get the quality back up. The fish all seem to love it.
 

Pete

Member
May 19, 2009
291
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North wales
I'm using R/O water
I would not do such a large water change with tap water, but R/O water is low on oxygen too tho so I would probaly be better doing little and often
Not having any problems just that article I read on the Think Fish site on water changes made me think a bit
The plecs esp the Royals are doing well , just thinking if the nitrates are low I dont need to do large water changes just more regular poo vacuums as matt suggests
Thanks guys :clap:
 

macvsog23

Pleco Profiles Team - RIP FRIEND
May 1, 2009
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71
Bristol
5% every 2 or 3 days

Water is RO |& HMA mix to a TDS of around 150 the mineralised to a TDS of around 200

Tanks are neverr vacuum cleaned but striped and cleaned every few months.

Most tanks contain a clay flowerpot with a small plant in it

All tanks have a power head with a fine sponge filter over the intake this will trap most muck and saves vacuum cleaning

Regards Bob
 

dw1305

Global Moderators
Staff member
May 5, 2009
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Wiltshire nr. Bath, UK
Hi all,
Does depend on the quality of the water, I use 10% rainwater change every day. Assuming your water supply is stable good quality water you can't really change too much water, but it maybe that this is more than you need. R.O. should be re-oxygenated with an air stone.

Because my water change is cold (I do microwave a small proportion of it in the winter) it will be highly oxygenated (and contain ambient levels of CO2). I also partially do a water change because the water butts contain Daphnia, "trickle feeding" the fish.

In heavily planted tanks you don't get the build up of nitrates that you would otherwise, and I've left the tank for a fortnight without water changes (and a couple of times failed to turn the filter back on and left it week without noticing) without any ill effects. I probably wouldn't have got away with this with more bioload, or if I kept Panaques etc.

cheers Darrel
 

Irene0100

UK Support Team
May 14, 2009
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Norfolk, UK
I do small changes on most of my tanks every few days, or every day on some tanks where trying to breed. but not 40% unless I suspect a water problem -eg ph a bit too low etc.
I thought RO was good on O2 but low in CO2 ! lol. so I always stand it for a few hours or overnight before using to allow it to balance.
 

dw1305

Global Moderators
Staff member
May 5, 2009
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36
Wiltshire nr. Bath, UK
Hi all,
Hi Irene there is no inherent reason why R.O. should have less or more oxygen than any other water, it is going to depend what sort of container you store it in. Theoretically as you add solutes (salts, calcium - Ca, etc.) to pure H2O it can hold less oxygen, but in practice this is irrelevant for fresh water aquarists (but not marine keepers).

If your R.O. water is kept in a wide shallow container with some surface turbulence, it will be fully oxygenated, if it is kept in a deep container with a small surface area it needs re-oxygenation.

Tap water may contain larger amounts of CO2 than it would naturally if it is under pressure in the water main, although it will out gas when the pressure is released (just like the relea of bubbles when you open a carbonated drink)

cheers Darrel