Percentage For Weekly Water Change

[Lady J]

Hi all,

What percentage of water do you change out weekly?

Thanks.

 

[Man of fish]

I usually do about 50% on most of my tanks, but it depends on the stocking and filtration level IMO.

 

[Lady J]

Thank you for your response. Well, at the moment I only have a betta in my 30g. wide so I probably don't need to do much yet. lol Just wondering though for the future.

 

[Alm0stAwesome]

I do 40-50% per week

 

[JohnDyer]

I do 20-50%, depending on how dirty it looks.

 

[cornclose]

15% a week for me. Any more and I lose too many nitrates and the plants don't like it or it requires more ferts adding.

I try to stick around 45-55 mg/l and the plants thrive. 15% a week maintains this.

Filtering is important too though, so ymmv.

 

[Dazzler666]

I do around 30% weekly as helps maintain the parameters and doesnt change water temp, nitrates, etc too much!! . Although ad you no doubt aware, if youfind a dead fish or find ammonia or nitrite in your tank then i do a
Substantial 50%+ water change!!
Hope this all helps.

 

[ZoddyZod]

the main purpose of the water change is to remove excess of nitrates - the percentage you do should aim to bring the nitrate level down to a similar level as your tap water. Therefore you will need to assess what works for you and your tank.

water changes also replenish any mineral content that may have been used up by plants and fish between changes.

 

[Ruthc1985]

15% a week for me. Any more and I lose too many nitrates and the plants don't like it or it requires more ferts adding.

I try to stick around 45-55 mg/l and the plants thrive. 15% a week maintains this.

Filtering is important too though, so ymmv.

I have to say, sounds pretty similar to mine - I do 15-20% a week (basically I remove a mop bucket's worth of water, and replace that) and it seems to keep on top of my nitrates, which are highish in my tapwater anyway (Do you find this in the Notts area cornclose?...I am Ilkeston area and tap nitrates are high). If anything I think I am putting nitrates into my tank for my plants to use lol

 

[Lady J]

Thank you all for your responses. Perhaps it would be a good idea if I tested my nitrates every week to see where they're at. Their level will then determine how much I should change out. I'm so new to planted tanks and am very unsure about keeping one healthy. I didn't know that you should keep nitrates in the water if you're dosing liquid carbon and using fertilizer tablets. Is there a target level for nitrates: healthy for the plants but not too stressful for the fish?

 

[ZoddyZod]

if you want to understand planted tanks in more detail then I would suggest starting a thread in Planted Chit Chat. Water changes, nitrates, ferts etc. can all be explained better for plnated tanks by the folks there.

 

[cornclose]

I have to say, sounds pretty similar to mine - I do 15-20% a week (basically I remove a mop bucket's worth of water, and replace that) and it seems to keep on top of my nitrates, which are highish in my tapwater anyway (Do you find this in the Notts area cornclose?...I am Ilkeston area and tap nitrates are high). If anything I think I am putting nitrates into my tank for my plants to use lol

I did test my tap water a while back but forget the exact Nitrate level - I seem to recall about 35 mg/l, which was a lot higher than I was expecting.

I water change with conditioned RO water anyway so Nitrates going in with this water is zero.

 

[Ruthc1985]

Ahhh fair enough but yes, 35mg/L does sound about the same as mine

 

[Lady J]

Again, thanks for helping me. It's apparent that I need to read more even though before I started I read a lot. Initially I was going to test the nitrates originating from my tapwater and truthfully, I just forgot to do it. I think I best do it now to see where the level is at. To restate from my earlier post, I didn't realize that plants need nitrates even when a person is dosing carbon in addition to using fertilizer tablets.

 

[cornclose]

Plants need Nitrates regardless of where it comes from. Nitrates are a beneficial natural by-product of the filtration system - when kept to sensible levels of course. In my experience, providing you have a good, healthy and correctly sized filtration system, adding Nitrogen using ferts can be reduced if not eliminated.

Of course, having a heavily planted tank will keep Nitrates much lower than what they would ordinarily be anyway, and if everything else is nicely balanced will allow you to do smaller water changes (still keep the frequency no more than once per week though...). In addition, doing the water change with conditioned RO water (which has no Nitrates in it) will also allow you to reduce the amount per change.

These two prime reasons allow me to 'get away with' only a 15% change per week. I'd be wasting time and effort if I were to change any more.