How many water changes do i do to a tank that is just sat up?

my tank has been sat up for a week now, 7 days. and i have some fish in it. how should i do a water change. the ph is way to high so what should i do cause the ph is over 8.5, off the chart. and i am mad.How many water changes do i do to a tank that is just sat up?
Note: I'm assuming you're talking about a saltwater tank.



Water changes are a very good idea for any tank because they are like a reset button that can remove excess nutrients, toxic compounds, and replenish lost compounds.



IMO, doing weekly or biweekly water changes of 10-25% (or more) is a great idea. To do a water change you need a few things:



-siphon (like a gravel vacuum or vinyl tubing)



-pump (like a maxi jet) that can be used for mixing the saltwater and that can connect to the tubing so you can pump water into the tank



-bucket or rubbermaid trashcan/tub; have some tight-fitting lid if you're going to store the saltwater for a while



-heater (doesn't need to be fancy)- the dials are often inaccurate unless you use a thermometer to check the actual temperature



-digital/alcohol thermometer (digital is easy to move and read; alcohol is likely to be more accurate)



-salt mix (for a simple tank without many corals, something like Instant Ocean is fine)



-freshwater- it is possible to use tap water if you have checked your water treatment plants water quality report. However, it is good to rely on some sort of filtered water (such as RO/DI or distilled) so you don't introduce nutrients like nitrates/phosphates that encourage nuisance algae blooms. Distilled is sold in grocery stores (avoid bottled water that has minerals added to it), and RO/DI is often found at your local fish store (LFS) that has saltwater tanks.



To do a water change, you add the freshwater, add the salt (usually 1/2 cup per gallon for s.g. of 1.023; add a little more for 1.025), mix with the pump/heater in the bucket. You want the water change water to be the same temp/specific gravity as that of the water in your tank. Use a vacuum/siphon to remove the water from the tank (this is a good time to siphon detritus from the rocks/sand), then use the tubing connected to the pump to add the new water.



For your pH, I strongly suggest checking your pH test with either your LFS or another kit. Some kits, like test strips or Red Sea kits are notoriously inaccurate, and something like the API saltwater master kit is enough to check pH. That said, a pH of 8.5 is at the ';high end of the normal range';, and new tanks often have wide pH fluctuations. I would go into more detail, but the link below is a very well-written explanation of various pH problems. It may seem confusing with all the chemistry terms, but the author is a chemist who is very good at explaining what could be happening in your aquarium. One simple way to lower pH is to get more aeration in the tank (like aiming a powerhead near the water surface) so that more carbon dioxide dissolves into the water, forming carbonic acid. You don't want to have a bandaid solution until you find the root cause of the problem.How many water changes do i do to a tank that is just sat up?
Well i change 20% of my water one every 2 weeks. And they are fine. Every 4 months i change the filter foam. Every month I rinse the filter foam. Take out any real plants as they can Disturb the Ph.
20% a week. If the fish are new to the tank they'll be nervous thats why your PH is high. Heres a great link saltwaterfish.com Its a store and theres a forum where you can ask questions. You'll need a PH buffer to bring down the PH level. Water changes frequently and add only 1 fish a month. Good luck.
WOW you should have waited 6 weeks until you put fish in it.

What is the ammonia at?



We need to know what size tank you have and type of fishes
What is the pH of your tap water? Take some, let it sit out for a day, and test it. If you tap water pH is high, there's nothing you can do for it. It's best not to mess with it with buffers, and limit yourself to fish that can tolerate that pH, like rift lake cichlids and certain rainbowfish. If your tap water is much lower, what do you have in the tank? If you have any calcium-based rocks or gravel (crushed coral, tufa stone, etc.) these can raise your pH too.



Weekly 25%+ water changes. If there's ammonia in the tank, step that up to 2-3x per week.
Take a siphon and suck out all the debris in the gravel into a bucket, meanwhile removing 20% of the water. You can do this every week to begin with, but later on you can get away with once every 2 weeks. Then get some new water, condition it and add it to the tank. The pH levels are usually really high when you first start your tank. Buy some Cycle by Nutrafin and add it every after water change, that will really help with the cycling process.