R/o top off

[rikstar]

Hello guys, new member here, I've just started up my first planted aquarium. It does run a sump. It is an ex-marine setup so I do have the top off chamber at the end of my sump. Now I was wondering, It takes a week for my top off chamber to fully run out of water. Due to evaporation! I was thinking if I could add my fertiliser to the water in the top of chamber, and let it top off the tank as it goes through the week, which will also be adding the fertiliser the same time, Would this be better, ive read on the back of most fertilisers that dosing through the week rather than adding one big does at the end of the week (After water change) is a better way of doing it 🤔 any thoughts
Cheers
Rik

 

[seedoubleyou]

You could. But I’d argue it wouldn’t be consistent. Especially in summer when the ATO would run out faster.

 

[rikstar]

So in the summer if I go through 2 of my top off chambers per week, As long as one has the week's fertiliser in it, it should be okay. if not, the alternative is to put a whole week's fertiliser In, in one go?

 

[seedoubleyou]

Hopefully someone on here does what you’re suggesting and can better advise.
Personally I’d just use a dosing pump if the idea is to spread the dose out over the week.

Adding it to your RO, could use it up in a week over winter, or 2 days in summer, it seems like it’s against your point of having it spread out.

 

[MichaelJ]

Adding it to your RO, could use it up in a week over winter, or 2 days in summer, it seems like it’s against your point of having it spread out.

Interestingly my evaporation is much, much higher in the winter than in the summer. Here in Minnesota the air is bone-dry in the winter while humid in the summer. Temperature around the tanks stays fairly consistent however.

I have a slight difficulty visualizing how this sump chamber top off system works, but I would think it easily could lead to inconsistent dosing if the dosing would depend on evaporation - as you said.

Cheers,
Michael

 

[DeadFish]

I've attempted this before and it's not so much that it doesn't work, but more so that it doesn't work well. As said before, there's a lot of variables that factor into evap top off. Temp, humidity, surface agitation, etc. Sometimes I go through 20L a week in top off, sometimes 5L. Another issue I noticed was that in my case, my ATO isn't particularly good at topping off at the same water level. Sometimes the sensor doesn't kick the pump on until it drops a cm, sometimes 1/2 a cm. All in all, it's inconsistent, and one thing I have learned in this hobby is that consistency is key. Not to say it doesn't or couldn't work, it's just another variable that I don't want to add into the equation. There are enough already. It's easy to manually dose and not much $$ to get a decent dosing pump. The Chihiros unit is a nice kit, but the Jebao ones can be had for about $60 and you can make your own containers.

Edit: this also doesn't work well for Micros that are more bioavailable at lower pH's and ideally dosed during the photoperiod. There's no way to time the dosing with an ATO.