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EI dosing for 14,500 litre aquarium!

enviroman

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11 Oct 2009
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Location
Chiswick
I am installing a huge 5.5 metre long, 14,500 litre planted aquarium at the moment.

My question is regarding EI fertiliser dosing. No off the shelf fertilisers are concentrated enough to provide sufficient macro and micro nutrients. However, I will still need to increase the dosage of EI powders per litre of solution to ensure I don't need to use litres of ferts every day.

I will be using a dosing computer with peristaltic pumps to ensure regular dosing.

1. Does anybody know the maximum amount of grams of EI powders per litre of dosing RO water I can use to ensure they remain in solution? Ideally, I would like to have a minimum of one week's worth of each solution attached to the pump. There is probably enough space by the sump for 4 vats @ 10-15 litres each. I hope this will be enough.

2. Also, has anyone any idea how Lisbon aquarium doses their aquarium? Would be very useful to know!
 

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You can get things like this that dose powders, so could dose the powders straight into the tank.

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The solubility of most of the macro salts is quite high, so from Wikipedia

KNO3 is 316gr/L at 20'C
MgSO4 (dehydrated) is 350gr/L
KH2PO4 is 220gr/L.

So you could probably easily try mixing at x10 strength and the salts should dissolve. I can't remember my physical chemistry but the limiting factor will be the common ion (K in this case), limiting the solubility of the two potassium salts. Note the MgSO4 is normally MgSO4.7H2O, but I suspect the extra water will not make much difference.

At x10 mix that would get dosing down to 5litre per say (at 20ml per 50litres).
 
Thanks Ian,

I will look into the powder dosers.

However, If I do use solutions, and I keep each individual chemical in its own solution, I assume that would mean the K will not be as limiting? So three different containers plus one for Trace element solution. Each container could then be smaller I hope. I could also alter relative amounts of NO3 and PO4 as needed too.

I also assume Trace elements will not be as much of a problem as I will be dosing much less of those.

I can have up to 4 peristaltic pumps linked to one dosing computer, so this should be achievable.
 
If you are dosing 3 macro solutions you night be better to dose saturated solutions, so you minimise the amount of liquid pumped each day.

So poor in lots of the salt into a say a 10litre container, add RO/boiled/distilled water and then dose the saturated solution. Need to check there are no issues of salts crystallising in the pipes etc.

You need to estimate the strength of the solution from either the solubility values (Wikipedia) or say get 100ml and evaporate it and measure how much dry salt is left.

You could also auto top up as well....if automation is your thing, though would have to think very carefully how to sense the water level in your top up tanks so they don't jam/mis-read due to salts crystallising.
 
This is no help whatsoever :sorry: but i have to say that is some tank you have there. If it's not being too nosy could you give any details of the plans for this and where it's installed ,thank you
 
Or you could just check the solubility of each compound in the EI mixes ;)

eg, potassium carbonate

Solubility in water (g K2CO3/100 g H2O): 105.5 at 0 deg C; 108.0 at 10 deg C; 110.5 at 20 deg C; 113.7 at 30 deg C; 155.7 at 100 deg C

Strangely this sort of data is well defined & readily available :wideyed:

:D


Note you don't want to work with the "saturated solution" as precipitates will form in tubing etc, instead one always uses a "working solution" which is dilute enough to avoid precipitation in either the stock container or in tubing etc.
Even slight amounts of evaporation or decrease in temperature can lead to that "saturated" stock solution crystalizing/precipitating completely out of solution.

Great project - do read through some of the bigger tank journals (here & on web)

How are you intending to plant/trim/adjust planting etc - make sure you're able to swim/move freely about the tank for maintenance
There are some videos on the Lisbon aquarium build showing filter outlets etc
 
Sorry I cannot give you any advise on EI. I am just writing this post to plead with you too keep a journal of this tank build.
 
While I got only a tenth of the water you're planning I think I can give you a few tips. First of all (I know people love EI here) but do you really want EI?
Lissabon doesn't use it, and this is for a good reason. EI tanks run great as long as everything is kept up, but as soon as something goes wrong (for example CO2 runs out) everything goes wrong quick (algae grows very fast). No problem in a small tank but to clean 14500L, you better take off a few weeks from work. That is why all tanks from Amano run very lean on PO4 and NO3 and traces, only K is provided in large amounts.

Think about that before you start EI.

Whatever you pick, never use saturated stock solutions indeed (10% less at least) and you'll be fine!
 
EI dosing would mean that you need to do a 7000L water change weekly!

eitherways, would love to see this tank in evolution.
 
EI dosing would mean that you need to do a 7000L water change weekly!
At £3.20 per 1000litres for me on a water meter that's £22.40 a week in water....yet alone heating, light and fertiliser...
 
Wow what a project, does it really matter about exact dosing?O,n larger tanks,smaller than this mind you,experts often recommend EI.Just dose to recommended starting guidelines to begin,such a amazing tank ,A discussion with John Whelan or TNC and ,Plantbrain will definitly have a guideline,would be the way forward
 
At £3.20 per 1000litres for me on a water meter that's £22.40 a week in water....yet alone heating, light and fertiliser...
Damn, water is expensive over there, here about 0,23 euro per 1000L. So cost is not my point, but mainly the work/time. Off course you can automate a lot, but I would still recommend a more lean method like ADA does.
 
Hi, what a huge tank! :thumbup:

The first question is already answered.
The second one, i don't know for shure... But i suspect that would be something similar ADA fert regime.
Far less than EI. Don't forget to add plants (as said before) and light to the equation. Maybe a softer approach is sufficient or even better! (only you can tell what's gonna be inside the tank). Check the 'Florestas Submersas' videos and topics, there are some good information and tasty inspiration. Look at those plants...:bookworm:
Without knowing what you planing, i advice to reflect about 'active' substrate and substrate fertilisers as cheap and easier method...

Maybe you can tell a bit more about this huge project,;)
cheers
 
EI dosing would mean that you need to do a 7000L water change weekly!

eitherways, would love to see this tank in evolution.

precisely, this question in my mind brought me to this section, I am scratching my head just with 400L of tank, I cant imagine 14500L.
just curious to know how people with large tanks do with EI dosing and water changes at the end of the week...
any heads up?

Madhav
 
Epic!

Your plant preference for this tank would be very slow growers, super low maintenance levels. Full EI levels aren't necessary to achieve this. I'd keep nutrient levels pretty low and aim for a water change of 20-30% fortnightly/monthly.
 
Thanks for all the tips and advice. It is a massive project, but sadly not my own tank. I will be maintaining 1-2 days a week once it is finished though. I am just ordering the aquasoil and power sand Special today. My latest thoughts are to go with Seachem products as needed (Flourish, Flourish Trace & Potassium) as they are the most concentrated I have found so far. I have used them all with great results in the past. It seems a good plan to run it quite lean on an added fertilisers, testing as appropriate.

I am planning on doing weekly water changes through draining the 2,000 litre sump with additional syphoning direct from the tank as required. The water supply is HMA filtered, with RO top up. My Clients wants Discus though, which has it's own additional difficulties!!!! I imagine he will eventually want around 200 in there, which I will source from Stendker Discus in Germany to ensure they are ok with local water(pH of 7).

I am test filling today and taking PAR readings at bottom of tank....A nerve-racking moment! Also, I am growing on about a third of the plants emersed to give them a good start.

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I am planning on doing weekly water changes through draining the 2,000 litre sump with additional syphoning direct from the tank as required.
Remember water changes are more than just water changes, vacuuming up the detritus, "brushing the plants" etc are equally important.

I did what I expected to be a simple "water change" yesterday (after having only done 5 days ago), before going away on holiday, and I was surprise the detritus I ended up removing. Blooming dirty fish and plants....
upload_2016-7-22_9-55-41.png
 
Hi all,
My latest thoughts are to go with Seachem products as needed (Flourish, Flourish Trace & Potassium) as they are the most concentrated I have found so far.
You really need to use dry salts, otherwise the expense will be enormous.

You can use a <"nutrient calculator"> for dry salts.

It doesn't matter which compound they came from, every NO3- ion is the same as every other NO3- ion.

cheers Darrel
 
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