SCUGrad

Check and see if I have my facts right: you make a 30-40% water change weekly because the nitrate levels will eventually rise to a level where it's toxic to fish.

Question: would it make sense to test your water for nitrates before water change and if the nitrate levels are still low (I have an understocked 75 gallon tank) to postpone water change until nitrate levels are up to a certain level? If so, what do you think that level should be?

Rationale: When I do water change on my 75 gallon tank, it takes a couple of days for the water to clear up. If I do this weekly, I will only enjoy pristine, clear water in my aquarium for a few days then I have to change the water again and make it cloudy. I'm trying to see if I can do my water changes biweekly instead of weekly.

Thanks for your help.

Shawnie

if your tank is cycled and the nitrates are under a certain amount (each member prefers different ratio's ...if mine are over 20ppm, I do a water change) that you are comfortable with, then do your changes.....on my overstocked tanks I do them once a week..on my understocked tanks, I do them every couple weeks.....I have a concern on yours tho because of cloudyness...are you doing a good gravel vac when you change out the water? although cloudyness is common as things get stirred up, it shouldnt last more than a couple hours after a water change if you arent overfeeding and your filter is the proper size...especially if you are understocked

Lucy

If your nitrate levels are low and you're not over stocked, that should ok.
But, remember we change the water not only to keep the nitrates low but also to replenish oxygen and nutrients found in the fresh water.

Why does you water get cloudy after water changes?

SCUGrad

It's the debris from the gravel. I usually stir it up to clean out the substrate a bit.

How low is low? 5? 10? When does it become kind of high?

Lucy

I consider 20 high. To me, 5-10 is perfect.
For now, maybe you should do twice weekly gravel vac and get the excess stuff out of the gravel.
Like Shawnie said, it really should clear up in a couple of hours.
Isn't it kind of depressing to do a water change and vacuum only to have stuff floating around when you add new water? I hate it! lol

aquarist48

Good morning. Water changes need to be done regularly. Once your tank is established (over the months and years) and you have your routine developed with water changes, testing will not have to be as frequent as long as your not adding new fish or critters. As mentioned above not only does the water changes help to keep our readings in tact but so many more beneficial bacteria are replenished as well that dissipate over time.

If you're wanting to change from weekly water changes to every 2 weeks, don't decrease the amount of gallons you replace. Example: If you change 5g's every week now, then change 10g's every 2 weeks. Try it and see, check your readings and go from there.
Keep us posted!
Ken