Water Change Neccesary?

[kim03333]

hi i have got a 22 gallon tank set up for a few months. it is cycled as i have had readings of zero for ammonia and nitrite for a few weeks. i have been changing about 25% of the water once a week. however, i have also had low readings for nitrate (about 5 - !0 ppm). is the only reason we do a water change to get rid of nitrate? if so it is pointless to do a water change as i have low nitrate anyway? i dont know why it's this low i only have 3 live plants in the tank and i dont have much algae. maybe the test kit is faulty although it's nutrafin so a good brand. anyway, assuming the reading is corrct, is there any point doing water changes?

 

[three-fingers]

Yep, if the plant's are growing well enough to actually impact your nitrate readings, then they will need all the right nutrients present in tap water, stop water changes and they will run out of one thing and stop growing well, then your nitrates will rise.

If you add all the exact nutrients the plants need separately, stock wisely, and top up for evaporation with distilled or RO water, you can probably avoid water changes.

If you top up for evaporation just with tap water, you will get potentially very harmful build up of minerals that don't evaporate.

By far the easiest, fastest and safest option is just to do water changes every now and then. Doesn't sound like you personally need to do it weekly though.

Unless you have sensitive species like maybe blue rams or guppies/mollies, anything up to 100ppm should be perfectly safe.

Keep the stocking you have, and try monthly water changes, might want to watch plant growth, but you can always add some fertiliser for the plants to be safe.

 

[minxfishy]

Fish also get nutrients they need from the water, so fresh water is needed for them to replenish these nutrients.

 

[kim03333]

thanks guys. i don't mind doing the water change, i just thought i'd ask about it otherwise i would keep thinking about it. u know what its like when you have a burning question.
the successfulness of my plant growth is mixed, i have 3 different plants. i dont know what species they are but one is growing very quickly. another doesn't seem to be doing much, but loks healthy enough and the other one kind of looks ill lol. i think it's the crappy substrate i have for them, it's not fine enough. anyway thanks alot for the answers.

 

[RedeyesUK]

True story:

I used to be fairly slack with my water changes, doing maybe one a month. A few months ago, I decided, having read up on here and elsewhere, that once a week would be better, so started that regime.

I've got a couple of plants in one of my tanks, that have stayed pretty much the same for about a year. Since I started weekly WCs, these plants have pretty much exploded into life - one of them is now double the size it was 3 months ago. On top of that, everything looks a lot healthier than it used to.

So while it may or may not be beneficial (I really believe it is), it certainly doesn't do any harm!

 

[andywg]

It doesn't do any harm to do the water changes. Eequally, if your nitrates aren't rising fast, it doesn't do any harm not to do them for a week or few. The choice is yours.