noob question but parents don't belive me.

[duanes]

The beneficial bacteria that help cycle a tank, are not planktonic, they are not free floaters.
These beneficial bacteria are sessile, meaning they live of surfaces of objects as biofilm, objects such as rocks, substrate, glass, wood, so transferring old water does not do anything useful to aid in the cycling of a tank. The reason we use bio-balls, lava rock and other solid bio-media in filters is because that media gets colonized by bacteria, and the reason we put that media in the flow of filters is because those bacteria are aerobic, and do their best work in an oxygen rich environment where aerated water constantly passes over them providing respiration and food (in the form of ammonia and nitrite.

 

[KATALEKEEPER]

The beneficial bacteria that help cycle a tank, are not planktonic, they are not free floaters.
These beneficial bacteria are sessile, meaning they live of surfaces of objects as biofilm, objects such as rocks, substrate, glass, wood, so transferring old water does not do anything useful to aid in the cycling of a tank. The reason we use bio-balls, lava rock and other solid bio-media in filters is because that media gets colonized by bacteria, and the reason we put that media in the flow of filters is because those bacteria are aerobic, and do their best work in an oxygen rich environment where aerated water constantly passes over them providing respiration and food (in the form of ammonia and nitrite.

so in your opinion it wouldnt really work unless I transefered a ton of media?

 

[duanes]

If you immediately transfer some wet media, or some substrate, some rocks, something that has been submerged in the tank for a lengthy amount of time (maybe two months), old water does nothing.
Even with old media, if you cram too many fish in at once, you may get an ammonia spike, enough to kill the fish.

 

[KATALEKEEPER]

If you immediately transfer some wet media, or some substrate, some rocks, something that has been submerged in the tank for a lengthy amount of time (maybe two months), old water does nothing.
Even with old media, if you cram too many fish in at once, you may get an ammonia spike, enough to kill the fish.

just two tropheus, one on each side of the divider

 

[duanes]

2 Tropheus = no big deal, as far as cycling goes.
But I would imagine they are separated because you only have 2, they don't do well in pairs or even trios.
Tropheus do best in groups of around 10 or more.

 

[KATALEKEEPER]

2 Tropheus = no big deal, as far as cycling goes.
But I would imagine they are separated because you only have 2, they don't do well in pairs or even trios.
Tropheus do best in groups of around 10 or more.

yup! Divided

 

[Toiletcar]

i’ve filled smaller tanks (40g-125g) completely with water from my established 750g system and had no problems - ive also used old media from other tanks in conjunction with cycled water to add to the new filters -

GL!

watch the feeding and parameters

i also did not do any large water changes on the new tank for a while did smaller frequent ones...

I’ve done this too. OP should be fine.