Tuning your CalRx | Alternate method thats too easy

[ReeferBud]

@ReeferBud - I tried the OP method for a while (with Maxijet feeding CaRx), and had constant issues. However when you see the great work BRS has done in their videos they are basically sayin the same thing as OP. Effluent rate isn’t as important as PH. You just need it to be constant, and constantly the same. That way all you mess with is PH. I ended up getting a Kaomer pump. I set it at approx 30-35ml.min so it would not clog and forgot about it. Now all I change is PH. You will notice the BRS system proves the OP correct. The difference is that the effluent has to remain steady.

I was a CaRx newbie when I saw this post, and after my modifications its right on point.

They also mention measuring effluent DKH, but I always forget how to dilute it since Hanna DKH only goes to 20DKH. Anyone know how tro dilute for higher readings?

Additionally, and this might seem basic but: I always thought increasing effluent increased ALK. That’s not the case, decreasing effluent rate increases alk. Rationale is the lower the effluent rate the more time the water sits in the CaRx therefore increasing ALK output. It seems this is part of @ReeferBud problem ay 500ml/min. It doesn’t allow the dwell time.

To measure your effluent Alk, just dilute your water sample by half. Then test the Alk and multiply whatever result you get by 2.

You’re right that increasing the effluent rate should decrease the Alk concentration in the effluent. But if the increase in effluent rate is greater than the proportionate decrease in Alk concentration, the total Alk being delivered to the tank should increase [Alk concentration x flow] = Alk delivered to the tank. It’s this last value that I’m trying to calculate for my system and maximize out of my reactor.

 

[AquamanE]

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To measure your effluent Alk, just dilute your water sample by half. Then test the Alk and multiply whatever result you get by 2.

You’re right that increasing the effluent rate should decrease the Alk concentration in the effluent. But if the increase in effluent rate is greater than the proportionate decrease in Alk concentration, the total Alk being delivered to the tank should increase [Alk concentration x flow] = Alk delivered to the tank. It’s this last value that I’m trying to calculate for my system and maximize out of my reactor.

Thanks, now that you mention this, I now recall I was told to do 2.5ml to 7.5ml and divide by 4.

You dont trust the maximum concentration per PH BRS did? I know they used different media than you, but later on they did a video comparing the media’s and I don’t think ARM and TLF had that big of a difference. Check that video out and maybe you can extrapolate some thing out of it. You doing maximum concentrations measurements yourself would require taking the CaRx off line i would think.

 

[ReeferBud]

It’s not that I don’t trust the maximum concentration that BRS did, it’s that I can’t replicate that result with my reactor. At 140 ml/min, I’m only getting an effluent Alk of 12 dKH and that’s not sufficient to meet the Alk needs of my tank. I’m trying to figure out if I should be able to expect higher Alk concentrations at a higher effluent rate but I’m not able to find any information about minimum residence time in the reactor to reach Alk concentration equilibrium

 

[AquamanE]

Have you tried dropping it down to less than 50ml/min? Maybe in the 30's? Or maybe you need to switch media? I'm just trying to learn with you.

 

[yellojello]

It’s not that I don’t trust the maximum concentration that BRS did, it’s that I can’t replicate that result with my reactor. At 140 ml/min, I’m only getting an effluent Alk of 12 dKH and that’s not sufficient to meet the Alk needs of my tank. I’m trying to figure out if I should be able to expect higher Alk concentrations at a higher effluent rate but I’m not able to find any information about minimum residence time in the reactor to reach Alk concentration equilibrium

What pH are you running inside?

 

[GoVols]

This might help???

Do not tap your manifold for the constant stream. It just wont stay dialed in.

I use the Sicce .5 as the feed on my GEO 2 stage, in a clean area in the sump.

Rolling with this method pretty close to, two years and love it.

This is my out going stream for a reference.

As far as wasted Co2 with this method:

Well,
I'm still on the same 5 pound refill since February.

 

[ReeferBud]

What pH are you running inside?

I’ve been at 6.4 - 6.6 pH for a while

 

[ReeferBud]

Have you tried dropping it down to less than 50ml/min? Maybe in the 30's? Or maybe you need to switch media? I'm just trying to learn with you.

I could do that but even at 30 dKH, assuming I could get there, running at something like 30 ml/min would only get me 23,000 mg/day, and I’ve already determined that my Alk consumption is around 136,000 mg/day, so unfortunately I need to run much higher flow to meet the Alk demands of my tank.

 

[yellojello]

I’ve been at 6.4 - 6.6 pH for a while

Yea, only option is to run higher flow and more co2 to match. Just as long as the ph coming out isn’t affecting your tank ph too much.

 

[Makers Marc]

Will the carx media dissolve proportionally with ph higher than they recommend? Like will alk and ca be dosed in thesame ratio, regardless of carx internal ph?

 

[Breadman03]

Will the carx media dissolve proportionally with ph higher than they recommend? Like will alk and ca be dosed in thesame ratio, regardless of carx internal ph?

I think I read somewhere that it can change, but very well may be wrong. I’ll have to spend a few minutes on my computer to see if I can find it.

 

[AquamanE]

Will the carx media dissolve proportionally with ph higher than they recommend? Like will alk and ca be dosed in thesame ratio, regardless of carx internal ph?

That is supposed to be the goal. That has been the case for me for the most part.

 

[Randy Holmes-Farley Verified Community Expert]

Will the carx media dissolve proportionally with ph higher than they recommend? Like will alk and ca be dosed in thesame ratio, regardless of carx internal ph?

Calcium carbonate media will dissolve at any pH below about 7.7, and progressively faster and to a greater extent as the pH is lowered. Note that pH is a log scale so the effect goes up fast as pH drops.

 

[Makers Marc]

Calcium carbonate media will dissolve at any pH below about 7.7, and progressively faster and to a greater extent as the pH is lowered. Note that pH is a log scale so the effect goes up fast as pH drops.

Thanks. Just curious why ive read some manufacturers state that the media wont dissolve optimally if internal reactor ph is above 7 for example.