Lowering TA is raising CSI. Keep TA higher?

[tomfrh]

Current levels are:

FC 6
pH 7.5
TA 90
CH 450
Salt 3800
CYA 70

Temp 16C

That gives CSI -0.32

I add acid to lower the pH when it exceeds 7.8, which also lowers the TA. I've been intending to let TA drop to around 60 before replenishing, as per TFP recommendations.

However, with a TA of 60 and pH of 7.2 I'd get CSI -0.83.

To keep CSI above -0.6 when lowering pH to 7.2 I'd need to keep TA at least 90.

Should I be leaving TA up around 90+ mark?

Or should I not worry about going below -0.6 for a little while?

Should I only be lowering pH to 7.4 or maybe even higher?

 

[jblizzle]

Stop lowering pH so much once the TA drops.

 

[tomfrh]

Stop lowering pH so much once the TA drops.

If TA is 60 I can drop to ph 7.5 without CSI going below -0.6

Is that what you mean?

 

[Jezza]

You may find that your pH may stabilise before you get to 60 anyway. How often are you adding acid?

 

[aussieta]

keep the ph between 7.6 and 7.8

 

[tomfrh]

You may find that your pH may stabilise before you get to 60 anyway. How often are you adding acid?

Every few weeks

 

[Jezza]

That's not too bad or inconvenient I would have thought. Yeah I agree - just drop it in small increments.

You may find you'll be good through to summer without doing anything in particular and then you'll probably be refilling with water containing TA anyway. Also as the temperature of the water increases it will give your CSI a kick in the positive direction.

As this stage I wouldn't go chasing a specific number on the TA.

 

[tomfrh]

At some point I’ll need to add bicarbonate though won’t I? The acid will keep pulling it down?

im wondering where to set the TA floor...

 

[JamesW]

If you keep the pH at about 7.8, the TA should be good at 60.

 

[tomfrh]

How would I keep it at 7.8? Add small amount of acid every few days?

 

[JamesW]

Correct, just add enough to lower to 7.8 and not lower.