Building my 11 000 gallon saltwater Tank - Discussion and Brainstorming

What do you think?

  • Sounds plausible at these costs

  • Plausible, but probably a little more expensive then anticipated

  • No way, this will cost a fortune more than anticipated


Results are only viewable after voting.

drjohntas

Feeder Fish
MFK Member
Dec 15, 2015
11
2
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70
Hi... just stumbled onto this discussion. I am in the process of planning a similar project but cold-water marine and more like 10,000 litres, but a lot of what you are churning over would be similar to my own journey. I have given myself 3 years planning phase. There are so many issues and each one is a subject in itself. I am actually very keen to stay in contact, not as an expert, but as a fellow traveller.
You talk about the issue of concrete. I have a 20 metre swimming pool a.. and yes it initiall developed hairline cracks.. but the cracks rapidly seal themselves as promised by my pool biuilder.
I recently discussed the issue of concrete and sealing with one of my patients who is a professional concreter and has been involved in building cement aquaculture vessels.. we have a huge local salmon aquaculture industry.
Here are some of his words of advice to me:


65 mm RULE
Her says the rule they follow with any cement structure anywhere near salt water is to keep REO a minimum of 65 mm from the surface.
You can buy 65 mm bar clips to ensure this distance

Type of REO
Says steel is OK if keeping to 65 mm RULE
He says you can use galvanised reo (costs more)
Also can get the reo-mesh hot dipped if want to.
He says can get stainless steel REO but that is going too far.
He says other products (plastic/carbon fibre) are a bit new and experimental

XYPEX
Xypex Admix can be added to cement to improve water-resistance. Says it makes the cement a bit gelatenous at first and he is not sure if that would be OK with shotcrete application. (I am thinking of shotcrete to apply cement as per swimming pools)
Xypex website has references to large aquarium projects using their products.

QUOTE
In June of 2012, the Saint Louis Zoo opened its new Sea Lion Sound exhibit – an
$18 million, 1.5 acre habitat which houses 11 California Sea Lions and a harbour
seal. The exhibit includes a series of streams and waterfalls, as well as a deep
saltwater pool with an underwater viewing area and 35 foot long viewing tunnel –
the only one of its kind in North America.
Xypex Admix C-500 was chosen to waterproof and protect concrete throughout
the exhibit. A total of 4,800 lbs (2200 kg) of the admixture was used in both the
shotcrete for the rockwork (about 1200 cubic yards/920 cubic meters) as well as
several cast-in-place concrete walls. The largest component, the pool, now holds
258,000 gallons of salt water.

One Pour or Two
He says aquaculture has specified single pour (floor and sides) at some times.
Other times they pour base, then add a black, sticky seal then pour sides.
He says you can grout the edges.. fits my idea is of a curved edge like our swimming pool.

My own project: I plan the inside of my aquarium like an arch on its side with the flat "base" of the arch as the viewing window to an adjoining room. The aquarium will be in another space and I will build a wooden jetty across the aquarium with wooden piles into the aquarium to aquascape it to resemble a real jetty. The jetty will allow you to walk across/sit/fish/clean aquarium etc.. and leads to another room. I won't labour on about my plans but they also include a sunken jacuzzi with a sliding glass cover.
 

drjohntas

Feeder Fish
MFK Member
Dec 15, 2015
11
2
8
70
Just questioning you about your water exchange strategy. Apologies if I have misunderstood your setup. I would be very interested in your plans for sump/pumps/skimmers/filter medium etc etc.

also plans with English labelling would be useful.

My understanding is that your described continuous low-level top-up is not a water exchange. I have been led to believe that water exchange is the regular removal of a seriously substantial amount of water from the system (designed to get rid up of the accumulated build-up of a variety of contaminants) and replacement by a similar substantial volume of contaminant-free water.... a low-level continuous water top-up cannot achieve this purpose.

I you are indeed going to do substantial water exchanges anyway, then you are going to be adjusting your water-levels/volumes as part of that regular process. So evaporation losses etc are going to be covered during your regular water exchanges.

I doubt if truely useful water-exchanges can be automated.
 

PaLaKaT

Feeder Fish
MFK Member
Jan 24, 2017
27
14
8
32
Wow, That would be an amazing build! I can Only dream of having something like that. What is your budget for it? Honestly from what i learned, the costs add up like crazy very quickly. I recently built a 300 Gallon Salt Water tank out of plywood for my office and it cost me almost 10k with fish and all the equipment.
 

Evolutionnext

Feeder Fish
MFK Member
Jul 1, 2015
21
12
3
41
Just questioning you about your water exchange strategy. Apologies if I have misunderstood your setup. I would be very interested in your plans for sump/pumps/skimmers/filter medium etc etc.
Well, the plan initially was to start with a low bioload and let it run for a while until the ecosystem established.
The first equipment I was planning on is the aqua Medic system filter skim
https://aquamares.de/aussenfilter/2...7mcXirmUAEQkD4gPk_-L-T7P4WUPYY064EaAkcK8P8HAQ

It has a bio filter, sand filter, protein skimmer, UV and options for ozone. It is meant for 20 000 liters and should be ok for a low fish load to start with. Then.. eventually I would upgrade with additional protien skimmers or filters etc as required and increase the number of fish. Eventually I would also increase the lighting significantly and try to add some not so water parameter sensitive corals.... all progressively to give me time to learn and to keep kosts lower at first.

My understanding is that your described continuous low-level top-up is not a water exchange. I have been led to believe that water exchange is the regular removal of a seriously substantial amount of water from the system (designed to get rid up of the accumulated build-up of a variety of contaminants) and replacement by a similar substantial volume of contaminant-free water.... a low-level continuous water top-up cannot achieve this purpose.

Ok, let me explain the concept I have in mind a bit more clearly:

During the day I have a water level sensor that recognizes if evaporation has led to a drop in water level. Whenever this is the case it adds reverse osmosis water until the level is ok again. The water level is jsut a tiny bit under the level of the overflow. This system will always keep the right salt level in the tank automatically.

Then.. once per day or maybe once per week... I pump a larger amount of prepared salt water into the tank. The water level rises and flows into the overflow until it has reached the level of the overflow again. If I added 100 gallons during this step, 100 gallons of old water will leave the system. This should essentially be a water change. It is not 100% optimal because a little fresh salt water will also leave the system to some small extent, but i think overall this should work... or am I mistaken?
 

Evolutionnext

Feeder Fish
MFK Member
Jul 1, 2015
21
12
3
41
Wow, That would be an amazing build! I can Only dream of having something like that. What is your budget for it? Honestly from what i learned, the costs add up like crazy very quickly. I recently built a 300 Gallon Salt Water tank out of plywood for my office and it cost me almost 10k with fish and all the equipment.
Hi... well, I have some trouble keeping the costs apart from the house costs. One probelm is this:
If someone decides to set up a tank in a corner.. they dont count the walls and floor and ceiling as part of the tank cost. If you make a room just for the tank... you somehow do consider it the cost... so its not entirely fair as a comparison.

I am calculationg that the acrylic will cost me $15 000... the installation and sealing maybe another $10 000 and the equipment in the first stage another $15 000. That would be the minimum setup... then add a few thousand for salt and other stuff and the first setup is done. Then.. gradually I would expand the equipment depending on the parameters I am having problems with.

Power consumption wise I am hoping to stay in the 2 kw/h range at first to be expanded to maybe 7kw/h for lighting later on for some corals. This I would then like to cover with photovoltaic roof tiles (wainting for the tesla/solar city tiles).
 

drjohntas

Feeder Fish
MFK Member
Dec 15, 2015
11
2
8
70
OK.. I am talking as a novice.. but still.. as I am thinking through the same sort of issues I hope you don't mind me wading in with my comments. Water exchange to my understanding involves the initial removal of a considerable volume of aquarium water which contains unwanted chemicals etc, and replacing with nice toxin-free water. Your method sounds like simply diluting the aquarium water and forcing some of this diluted product out to waste. That does not sound like an effective way of improving water quality. Next.. forgive me for challenging you on this.. but shouldn't you add the RO water to your sump, not your tank.
Also I read that you need to add alkalinity to the RO water otherwise you will end up unbalancing alkalinity with the constant RO additions
 

Evolutionnext

Feeder Fish
MFK Member
Jul 1, 2015
21
12
3
41
OK.. I am talking as a novice.. but still.. as I am thinking through the same sort of issues I hope you don't mind me wading in with my comments. Water exchange to my understanding involves the initial removal of a considerable volume of aquarium water which contains unwanted chemicals etc, and replacing with nice toxin-free water. Your method sounds like simply diluting the aquarium water and forcing some of this diluted product out to waste. That does not sound like an effective way of improving water quality.
Thanks for your comments.. thats what I'm posting my ideas for after all.. ;)

Well.. my calculation goes like this:

I have 10 000 gallons in the tank. This water has been in there for a while so I call it "old". Then there is a tank of new salt water in the cellar ready to be used. Right salinity and all.

The tank runs for a while and 10 gallons evaporate. The reverse osmosis water tops up the tank to the original 10 000 gallons. Salinity is conserved. (ill talk about alkalinity later)

Then, once per day I add 100 gallons of "new" salt water. Now for ease of calculation, lets assume I closed up the overflow just before and I now have 10100 gallons of water in the tank. The currents quickly mix the contents and the new water is not thoroughly mixed in.

I then open the overflow and let 100 gallons of surplus water out of the tank. This water consisted of: 10 000 parts of old water to 100 parts of new water.. which is equivalent to 1 in 100 or about 1% of new water.

So 99% of the water removed is old water and 1% is new water.

So the loss of efficiency in the water change is 1% as 1% of the water I remove from the tank is actually new water. So you are right, it is not as efficient as first removing water and then topping it up with new water, but the 1% loss in efficiency is probably worth the ease of automation.

To clarify: My plan would be to actually replace 20 gallons per day as this would amount to a 5% water change per month. If it surfices, I would keep this up. If the parameters require it, I would increase the volume to be changed.

About adding RO water to the sump and not the tank.. thats new to me.. is there a specific reason for this?

About the alkalinity aspect.... hmmm.. as you are only replacing evaporated water I was of the opinion that this would not matter.. plus the new water is well balanced and buffered... but I might be wrong.
 

drjohntas

Feeder Fish
MFK Member
Dec 15, 2015
11
2
8
70
Hi again. Here are my reasons for adding RO top-up to the sump and alkalinity to RO water.

1. if you have a system involving a sump placed below your aquarium then you will probably employ a return pump in your sump which drives the flow for the sump-aquarium-sump circuit.

If your aquarium has passive overflow outlets to return water to the sump then the level of the water in the aquarium remains constant at the level of the overflow outlets, despite any evaporation losses. Similarly any section of your sump in which water flows over a divider will maintain a constant level at the height of that divider.

The only part of the whole system which suffers a drop in water level from losses (evaporation or otherwise) is the last section of your sump which houses the return pump(s).

So the auto-return mechanisms I am familiar with, rely on detecting this drop in sump water-level. For convenience they add RO to the section of the sump suffering water-level drop, not to the aquarium. I guess there is no logical reason you can’t add RO into the aquarium, but why do it when the general philosophy is keep the display aquarium free from the intrusion of maintainance equipment of any kind (wherever possible).

There are probably a number of variations on the theme, but the one I know about is described nicely in a utube video

Unfortunately I have not earned enough good-guy points on this wonderful forum to post a direct connection to this but search for Best value New UAC auto top up system!

2. The alkalinity issue is also explained in Why to Not to use straight RO or di
 

drjohntas

Feeder Fish
MFK Member
Dec 15, 2015
11
2
8
70
Getting back to your water change theory. I can't see how exchanging 100 gallons per day in a tank of 10,000 gallons can qualify as a water change .... if the basic reason for a water change is to get rid of unwanted materials/chemicals. In your huge system, expelling 100 gallons gets rid of nothing useful. You need to get rid of a serious amount of water in each exchange to make any impact on the concentration of toxins. I suggest that really big water changes once a month or so would be way more effective in maintaining water quality than your tiny daily exchanges.
 
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