Daily Water Change! Too Much?

[rodders666]

Hi,
I am going to be re-setting up my 4ft tank (been empty for a while). I have it all planned out in my head, but an advisor suggest a weekly water change of 40%. Ideally, I'd like to do this in 4 x 10% water changes, or basically do a 10% change every other day.
Is doing this ok, or is the large change for a reason?

Tank is 48" long, 15" wide 18" high/deep. I have a Fluval FX5 ready for it.

This is ~210 litres, but for my fish stock calc I based it on 180 litres.

Planned stock is:
- 12 Galaxy Rasbora
- 12 Gardneri Killifish
- 12 Badis Badis
- 4 Otos
- 4 Emerald Green Corys

An advisor gives stocking at 95% based on 180 litres.

As well as info on water changes, is there any preference as to what order I should add these fish?


Thanks ::

 

[TwoTankAmin]

Once a week 40% would be fine. Why do so much work for this with 4x10? But, there is a better chance of nasty things building up doing 4x10 than one 40% or even 2x20%.
 
If you assume that nothing bad is being added daily, then look at the difference between 40 vs 4x10.
 
Lets assume you want to deal with 100x bad stuff. Do a  40% wc and you have 60 left.
 
Now lets change 10% so at the end of change 1 you have 90 left. After change 2 you remove only 9, so you have 81 left. Then change 3 and you remove 8.1 and you have close to 73 left. With change 4 you remove 7.3 which leaves you with 65.7. So your way leaves about 10% more stuff you want out still in the tank, 60 vs 65.7. This is an over simplicfication but it should make the point.
 
if you cycle your tank using the directions on this site for fishless cyling here http/www.fishforums.net/index.php?/topic/421488-cycling-your-new-fresh-water-tank-read-this-first , you can fully stock a tank all in one go if you want.

 

[sawickib]

Now lets change 10% so at the end of change 1 you have 90 left. After change 2 you remove only 9, so you have 81 left. Then change 3 and you remove 8.1 and you have close to 73 left. With change 4 you remove 7.3 which leaves you with 65.7. So your way leaves about 10% more stuff you want out still in the tank, 60 vs 65.7. This is an over simplicfication but it should make the point.
 
if you cycle your tank using the directions on this site for fishless cyling here http/www.fishforums.net/index.php?/topic/421488-cycling-your-new-fresh-water-tank-read-this-first , you can fully stock a tank all in one go if you want.

wow... brain dead

 

[rodders666]

Once a week 40% would be fine. Why do so much work for this with 4x10? But, there is a better chance of nasty things building up doing 4x10 than one 40% or even 2x20%.
 
If you assume that nothing bad is being added daily, then look at the difference between 40 vs 4x10.
 
Lets assume you want to deal with 100x bad stuff. Do a  40% wc and you have 60 left.
 
Now lets change 10% so at the end of change 1 you have 90 left. After change 2 you remove only 9, so you have 81 left. Then change 3 and you remove 8.1 and you have close to 73 left. With change 4 you remove 7.3 which leaves you with 65.7. So your way leaves about 10% more stuff you want out still in the tank, 60 vs 65.7. This is an over simplicfication but it should make the point.
 
if you cycle your tank using the directions on this site for fishless cyling here http/www.fishforums.net/index.php?/topic/421488-cycling-your-new-fresh-water-tank-read-this-first , you can fully stock a tank all in one go if you want.

Exactly the sort of reply I was after, answered and explained why. So, I will stick to the weekly 40%, thanks.

The reason I was thinking smaller more frequent changes was to as not affect the water temp etc too much but your explanation makes sense.

And yes, I will be cycling as per guideline on here. I got 500ml of Jeyes Kleen Off Ammonia for £1.50

 

[N0body Of The Goat]

Celestial Pearl Danios will not do well with larger, piggy eater or territorial fish. Keep them with placid, similar size species, for example Rosy Loaches (which they are found alongside in the wild).
 
Fundulopanchax gardneri can be a threat to smaller fish, I've had the closely related Fundulopanchax nigerians "Innidere" kill half my original Beckford Pencilfish group.
 
Otocinclus spp. and Brochis/Corydoras spp. (depending on what you mean by Emerald Green Cory) should be kept in bigger groups than 4, they are social species, 10+ is far better.
 
Badis badis are temperate fish, the others are low end tropical at least. Multiple males will need lots of line of sight barriers, in a group of 12 you might be wise to limit males to 3/4. 
 
Brochis splendens are great catfish in the right community, but they are built like tanks compared to everything else listed and they will push everyone else away from food at all levels (these will easily compete with many loach species, something Corydoras spp. will often struggle with bar exceptions like Pangio semicincta). 
 
It does come across that you are "shoe-horning" too many fish into this setup, even if you had not chosen five incompatible species. Also beware of the FX5 being rather powerful for small species, I've used one of these to make riverine conditions for chunky ~10-25cm SL rheophilic fish in 5 and 6 foot tanks before now. I fear you have fallen for the "get a massive filter, I can than add more fish" approach, when the overstocked tank is still going to result in lots of nitrates (especially while feeding several times a day while they are young and growing quickly) which will need removing with same amount of water changes as a more suitably sized filter for a ~200l community of small fish. 

 

[rodders666]

Thanks. I feel a big re-think is in order.

The Danio Margaritatus is the fish I like most, so will stock and design tank around those.

As far as powerful filter, yea I know it is, but it's not my intention that big filter means more fish.

I have designed a spray bar (with the help of my plumber father in law) that goes around the top of the tank and is hidden from view. This is designed to spread some of the power and make it less of an impact on the fish.

This is why I ask the questions, I can take all your info on board and amend plans.

Thanks.