few questions for the planted experts :)

[dbfzurowski]

1.When using co2, your ph in the tank drops, so how do you manage water changes if your tap is of higher ph?
Like my tank for ex, current ph 7.6 and kH 4.25* so i would have to pump co2 until my ph reaches about 6.7 to get ~17mg/l. My tap is 7.6 so how do you guys manage that?
Small water changes? Use peat to lower ph in storage tank?
2. I have a low tech planted and my nitrate is always below 5ppm. I haven't tried to slow down on wc as not sure if thats the way to go(i have discus in it). So how do you increase your NO3?? I've read that 15-20ppm is ideal for plants? Or do i add some fish?

thanks.

[Fraise]

1. to answer your question about the Co2 i think it depends how much water you change at once. my water is pretty similat to yours, about 7.6 PH and 4.5KH so i set my co2 controller to control 6.9 as the center value and .2 as the span. this keeps it between 6.8 and 7.0. when i do a water change, even if i do a 50% with straight tap water the PH will only rise to approx 7.2 which is not that drastic and i've also read on here that a PH swing up is not as harsh as a ph swing down.

2. I have a high tech setup and dose flourish 2-3 times a week. my nitrates haven't been above 10 in the past 3 months since setting up the tank.

[dbfzurowski]

1. to answer your question about the Co2 i think it depends how much water you change at once. my water is pretty similat to yours, about 7.6 PH and 4.5KH so i set my co2 controller to control 6.9 as the center value and .2 as the span. this keeps it between 6.8 and 7.0. when i do a water change, even if i do a 50% with straight tap water the PH will only rise to approx 7.2 which is not that drastic and i've also read on here that a PH swing up is not as harsh as a ph swing down.

2. I have a high tech setup and dose flourish 2-3 times a week. my nitrates haven't been above 10 in the past 3 months since setting up the tank.

I dose flourish once a week after my 90%wc on my low tech setup.
I'm thinking about going high tech in the future and was wondering about the wc. So probably the best way to do this is setup the tank without fish and just do wc and check ph, more/less % to see what works best.
Whats the max ph change that can occur with out stressing discus? Think i read .2 somewhere, is that correct?

[yikesjason]

I was told by some of the experts on theplantedtank.net that ph swings caused by co2 don't affect the fish the same as other ph swings. With the co2 off at night, you ph will come back up to its normal level. Try comparing the ph just before your lights and co2 come on in the morning to your tap. That would give you a more accurate comparison.

As for ferts, I don't track the ppm. But I dose dry fertilizers every day according to the EI method. One of the powders I add is KNO4. There are a few really good sources for it online if you are interested in dry dosing. It saves a lot of money over flourish.

[theblondskeleton]

I have my pH controlled at 6.3 from 7.4 out of the tap. I do 80% water changes weekly, and the last few times my discus have spawned within a few hours of the water change. When I change the water my pH goes up to 6.9, and drops to 6.3 within about 2-3 hours. I have done this for a long time without problems. I have to agree with yikesjason that CO2 pH swings are not as bad. It may have something to do with the fact that the water is well buffered, but I'm no chemistry expert. I just know my fish hardly pay it any attention at all :)

[exv152]

1.When using co2, your ph in the tank drops, so how do you manage water changes if your tap is of higher ph? Like my tank for ex, current ph 7.6 and kH 4.25* so i would have to pump co2 until my ph reaches about 6.7 to get ~17mg/l. My tap is 7.6 so how do you guys manage that? Small water changes? Use peat to lower ph in storage tank?

Age and aerate your WC water well and give it plenty of time to do so 24-48 hours. Make sure your tank has a good KH value, which you do, and the pH swings will be minimized. Keep in mind pH swings naturally occur throughout the day anyway. But a good KH value will keep the value in-check.


2. I have a low tech planted and my nitrate is always below 5ppm. I haven't tried to slow down on wc as not sure if thats the way to go(i have discus in it). So how do you increase your NO3?? I've read that 15-20ppm is ideal for plants? Or do i add some fish?

You can try adding some KNO3 which doses both K and NO3, but the most natural and best way to do it is to increase the bioload, gradually.

[alan j t]

i change a 1/3 when doing w/c. i dont to stress out the fish with the ph swing.