Adding 2-part via ATO water?

[Joshbd]

My new tank is all up and running now, and I'm just starting to need the assistance of an alk/calc supplement. I'm comfortable using 2-part solution, but it's kinda pain to do it manually everyday and dosing pumps are expensive.

So, why can't I just add a predetermined amount of 2-part into the five-gallon auto top off reservoir? The evaporation in my tank is fairly constant, so I'd have decent control. My only concern, I think, would be the calcium precipitating out. But as long as I didn't raise the levels to high by adding more 2-part than 5 gallons of RODI water can handle, I'm not sure why this would be in an issue.

So, before I waste RODI water and 2-part solution, is there any easy answer why this wouldn't work? Thanks.

-Josh

 

[tigerslacrosse4]

FWIW the dosing pump may save you alot of trouble in this situation. I'm no expert but what your saying right there spells CRASH to me. I would go on the safe side and do it manually or get a dosing pump. your plan is way to risky I would advise you not to do it. anyone object?

 

[delta]

It can be done. Maybe Dave MCreeferson will chime in on the subject

 

[DoctaQ]

i think the way to go here is to have one of your two parts in the top off and dose the other part manually but not dosing too close together i think is the key here.

if you add both parts of the two part into RODI they will just combine into calcium carbonate which is not useful.

you can get an aqualifter to dose your two part solution but i would test it thoroughly.

my setup doses 8oz of top off every day at 3 combined with alk supplement, then i have a bottle of ca supplement that i dose at night

 

[Dave McReeferson]

I have been doing this for a few years, and have kept a fairly high demand system supplied with it's needs by doing so.

There are a couple things I would like to suggest though.

First, either you will need two separate top off containers, or you will need to use top off for one component only and manually dose the other. As was mentioned earlier, you can not combine the two in one vessel.

Next, I am not really sure what you are using for a top off system, but I would recommend against using this scheme if it is not thoroughly reliable, and to some extent fail safe, especially before dosing your alkalinity component with it. Ideally, your top off system would be set up in such a way that it is impossible for it to deliver excessive TO due to stuck float switches, skimmers going crazy, or accidental leaks. I have found that the best way for me to accomplish this is to have a dosing system that delivers a steady amount of TO 24 hours a day. This way, it does not matter if float switches stick or skimmers go nuts, your top off will still only deliver x amount of top off water, the same amount it always delivers in a 24 hour period. This top off reliability can really be applied whether you dose with it or not. One of the most common causes of tank crashes is something resulting in excessive TO water being added, one of the other top reasons is excessive alkalinity swings. When you start dosing with your top off, you group two of these dangers together, so it is imperative that careful thought be given to your setup, otherwise you are inviting disaster.

IMO, this is an excellent means of delivering on your tank's needs. By having a continuous 24 hour feed, there are no sudden spikes or fluctuations as can sometimes be seen in manual dosing, and stability is the key to happiness in this game. Just remember to give careful thought to it before you go this route, if it can go wrong, eventually, it will, so be certain to cover all of the bases.

 

[Joshbd]

Adding 2-part via ATO water

Thanks! That's definitely helpful information. I like the idea of having a steady infusion of TO water rather than float switches, and it sound like an easy way to improve stability.

But, did you have a hard time exactly matching a constant dosing speed with evaporation? Or, does it only take a few minor tweaks throughout the year?

Also, just out of curiosity, I'm still not entirely clear on my I can't mix both directly into the TO water without precipitation. As long as I didn't raise the the calcium/alk in the TO water above a reasonable level, say for example 400ppm/8dkh, why would it be in issue. How is this different than adding both parts into my tank? Or, is the issue that the amount of 2-part supplement I need to dose is more than 5 gallons of water can safely accommodate without a precipitation issue?

 

[Takara]

Do you have a controller on the tank?

 

[DoctaQ]

the reason that two part does not combine together in your tank to precipitate is because the magnesium allows the concentration of both to be higher than they could be if the solution contained nothing but the two parts, which ideally is what you would be trying to make here with RO and calcium and bicarbonate.

 

[MikeG]

Have you tried or thought about using kalkwasser as topoff to see how close that would come to maintaining your levels?

 

[Joshbd]

Ok, interesting, so its the magnesium that makes the difference. That definitely makes sense. So, technically, if I added the magnesium first I could then dose all three simultaneously? I can see downsides to this, such as independent control of each supplement, and ensuring the TO water stays uniformly mixed, etc., but an interesting thought.

Really, I was hoping to try to regulate calc/alk/mag with the systems I have in place currently, but I guess a Kalk reactor is likely a better answer for me since it is more automated. Thanks for all the input, and feel free to pm me if you have a spare kalk reactor lying around!

And unfortunately, no, I don't have a controller. But a Digital Aquatics RKL might be on the xmas list. We shall see.

 

[Dave McReeferson]

the reason that two part does not combine together in your tank to precipitate is because the magnesium allows the concentration of both to be higher than they could be if the solution contained nothing but the two parts, which ideally is what you would be trying to make here with RO and calcium and bicarbonate.

Ok, interesting, so its the magnesium that makes the difference. That definitely makes sense. So, technically, if I added the magnesium first I could then dose all three simultaneously? I can see downsides to this, such as independent control of each supplement, and ensuring the TO water stays uniformly mixed, etc., but an interesting thought.

I am not a chemist, and frankly can not tell you why this will not work (I will leave that to someone else), but I can tell you that it will not. It is not as simple as adding magnesium to the mix to keep it stable. Outside of Kalk, there are no practical fluid supplements that provide both calcium and alkalinity supplementation together. Trying to combine your two part supplements in one container simply will not work.

Really, I was hoping to try to regulate calc/alk/mag with the systems I have in place currently, but I guess a Kalk reactor is likely a better answer for me since it is more automated. Thanks for all the input, and feel free to pm me if you have a spare kalk reactor lying around!

And unfortunately, no, I don't have a controller. But a Digital Aquatics RKL might be on the xmas list. We shall see.

Kalk is a method used with success by many reefers with reasonable levels of Ca and ALK demand. However, I would make the same cautions I made with the two part scheme for Kalk dosing as well. Kalk needs to be dosed with care, so be certain to put some thought into your dosing scheme.

 

[DoctaQ]

the whole adding magnesium to top off with alk and ca is kinda impractical, since mg needs to be about 3 times as high as calcium, by then you have a signifigant sg, not to mention that magnesium is usually bonded as magnesium chloride which means all kinds of fancy stuff, in the end youll just end up adding full blown salt water to your tank. haha.
kalk is the way to go here since its essentially what youre trying to do