Check out my stats, opinion?

[Tinajo]

I have a 35 gal. tank and have been doing 10% water changes every day due to old tank syndrome, which I learned about here. Now the stats are:

Amonia 0
pH 8.2
Nitrites 0
Nitrates between 5 and 10 ppm

Is it okay to now begin 50% water changes once weekly or do I need to keep lowering the pH and Nitrates slowly with the 10% once a day?

Thanks in advance!

 

[Rallysman]

Here is a thread/formula that I found to be pretty helpful.
I think you could get away with water changes smaller than 50% weekly with the same results.
This is copied from Monsterfishkeepers (dont take offence, I know it's kind of abraisive I'm just offering it for the formulas lol):

There are sooo many threads on WCs and I always encounter the same mistake:
People believe that 2 small WCs are the same as one big one as long as they change the same amount of water. It is wrong.
If you do 2 WCs, when doing the second one, part of the water you pump/suck/siphon out is the "clean" water you put in in the first waterchange.

Now here is formula I copied without permission:
"The waste in the tank on the evening (after a WC) of the first day = W(1-WC%)

Waste in the tank after second day (after WC) = W(1-WC%) + W(1-WC%)(1-WC%)

Waste on third evening = W(1-WC%) + W(1-WC%)(1-WC%) + W(1-WC%)(1-WC%)(1-WC%)

Etc., etc.


In English it means the fish are constantly putting out waste and it is being partially removed every evening with the water change, so the waste builds up over time. It is shaped like a learning curve where it is steep at first then gradually levels out to a nearly constant amount (the time to level out (flattening of the curve) varies with the WC% but is around one week for most of our situations). The actual curve if done by hours would actually form a sawtooth pattern but still in the general form of a learning curve."

For a more exact info click here

If you have difficulty understanding, you can do the following experiment:

Take a bottle of milk and perform small WCs on it. Try pouring out some 5% as some "small WC followers" suggest and refill with water. Shake and repeat. Shake and repeat. Shake and repeat. Shake and repeat. Shake and repeat. Shake and repeat. Shake and repeat. Shake and repeat. Shake and repeat. Shake and repeat.

You'll see that it will take you a whole **** day to get the water in the bottle absolutely clear. If you pour all the milk out at once and refill with water it will take a few seconds.

Of course a 100% WC is not an option for most fish and people.

Therefore the decision on how big and often you WCs should be, is a trade off between a big one that stresses the fish and a small one than stresses the fish-keeper.

Not thaaaaat complicated really.

 

[Rbishop]

I would be interested to know the pH of your replacement water, and have you been doing gravel vacs? New filter media? Do you have any GH/KH test kits to tell us what your tank water reads for hardness and the same on your tap water?

 

[Tinajo]

Yes, I do once weekly gravel vacume. I never thought to check the pH of the replacement water and I don't have anything to check the hardness of the water. And no, I don't have any new filter media.