[owlen]

Hi all,

I'm about to start using an automatic water change system. My tank is 80L, and I have a 30L sump of "fresh" water underneath it. I have an automatic system that will fill the aquarium with ~2L of fresh water daily, and of course an overflow for the extra water.
I'm using the following additives:

• Flourish Excel
• Flourish Phosphorus
• Bloom & Grow NITROGEN ("almost identical to Flourish Nitrogen" said the LFS)
• Flourish Iron
• and I use JBL Aquadur to keep my KH up

I would really like to automate the dosing by adding as many as possible of the additives straight to sump. I can easily calculate the amounts I need, but I'm not sure about:

1. Do any of these "negate" each other in any way? (Phosphorus and Excel?)
2. Do any of these will evaporate or lose their ionic properties? (Iron?)
3. Any other reason not to do it?

So far I'm doing a very bad job of keeping a constant regiment, and I would really prefer an automated solution, hopefully with my current WC system.

Thanks for any thought, idea or advice!

 

[Darkblade48]

Do any of these "negate" each other in any way? (Phosphorus and Excel?)

Most people generally recommend not dosing iron and phosphorus together, as they tend to form an insoluble ferric phosphate. However, it is possible to dose them, provided your water volume is large enough and you space the dosage apart (perhaps a few minutes, just to let the fertilizers circulate).

Do any of these will evaporate or lose their ionic properties? (Iron?)

Evaporation will be an issue in your stock bottles. Be sure to keep them covered.

Additionally, as the stock levels go down, there may be more evaporation/water that collects on the sides of the bottle, which may increase the concentration slightly.

Any other reason not to do it?

Hassle of preparing liquid fertilizers, I suppose? I like dosing liquid myself.

 

[owlen]

@Darkblade48 - thanks for your input!
I also went and asked the same question at on the seachem forum, and got this answer.

Based on the data gathered, here is my setup:
The sump is topping 2L daily. The tank is covered so there is almost no evaporation, and the overflow is about 2L as well.
For every 10L I add to the sump I add: (all amounts in mL)

• SeaChem Prime: 0.25
• Flourish Excel: 10
• Flourish Iron: 10
• Flourish Phosphorus: 3.5
• B&G NITROGEN: 1.9

In the future I might add Flourish Trace at 2.8.

In a couple of weeks I'll get a measurement of everything I dose and make adjustments.

If anyone has any comments/ideas I would be glad to hear!