A ~19,000 Gallon Aquarium

[nahham]

my question is: where does the skimmate go from the collection cup? i see the option of sending it straight to the ocean. which actually is in no way i see of dumping pollutants but rather returning the minerals back to nature

I agree on the returning minerals part. We actually had the same discussion on my local forum. What I'm thinking is that I can always use the saltwater well I have next to the skimmer. It is close and unused.

 

[Kerreefer]

if the algae scrubber fails i.e. it dies for some reason. every single bit of po4 it consumed is going to be dumped into the entire water column very rapidly...

 

[Kerreefer]

this thread is indead an awesome endeavor! iv'e scanned through mostly all of it, but i'm curious on something:

-- are you still using natural seawater recirculation?

-if so im wandering on the amount of skimming needed for the continuous bioload of the fresh ocean water itself, not to mention the load of the system.

-feeding the fish must be a HUGE load as is. plus trying to keep the incoming seawater cleaner than what it is for asthetics of your disp. tank. (visual affect)

 

[Renegade9]

Wow

Wow

This looks nice

 

[allsps40]

Dam came a long way. Holly skimmer. I think you made a very good skimmer there. Need to get that cup on it, be sure to have a drain in it. I would run the drain to the sea. I agree that you should look into Ozone your your tank it will be a great addition.

 

[nahham]

if the algae scrubber fails i.e. it dies for some reason. every single bit of po4 it consumed is going to be dumped into the entire water column very rapidly...

That is true. However, the water test did not show anything wrong in that regard.

-- are you still using natural seawater recirculation?

When I started the skimmer I stopped. However, evaporation was a major issue, especially in summer days like now where the temperature reaches 41C (105.8F). It goes higher as well, hence the shades. I started inserting a little bit of natural seawater which seems to be holding the salinity stable, does not change the water dramatically, and hold the water level stable. Until I can find an alternative to topping off with fresh water which was relatively expensive (150 USD a week).

-if so im wandering on the amount of skimming needed for the continuous bioload of the fresh ocean water itself, not to mention the load of the system.

I'm still experimenting with that.

-feeding the fish must be a HUGE load as is. plus trying to keep the incoming seawater cleaner than what it is for asthetics of your disp. tank. (visual affect)

It is and I am always amazed when the water clears up dramatically without any major changes. The only problem I face that persisted is the suspended particles that I haven't been able to take care of.

This looks nice

I'm glad you like it

 

[allsps40]

Wow not to bash you at all but you did not think about evaporation on a 18,000 gallon out door reef pool. This should have been planned out from the start on a build this scale. I also would not be using the sea water from right behind the tank and fish farm as you seem to be. All the boat traffic and being right on the shore like that there is a high amount of run off pollution. When large scale public aquariums use NSW the collect it out from the middle of the bay (using Monterey Bay Aquarium for reference) and then they still UV and Ozone treat it before it goes into the tanks. You may want to look into a large RO system for top off. As for salt water here in the States there are many companies that sell filtered clean natural sea water, you can by it by the tanker or seven as small as 5 gallons.

 

[socalireefdood]

shes skimming alright.. very impressive build. I bet you couldnt fall asleep some nights thinking about this. Haha.

 

[Reefski's]

the public aquariums also filter it through a sand filter. UC Santa Barbara pumps their water through a 20 micron sand filter, no ozone or charcoal. and theirs is a few hundred gallons a minutes flow through system through the school's marine science dept and back to the bay.

 

[nahham]

Dam came a long way. Holly skimmer. I think you made a very good skimmer there. Need to get that cup on it, be sure to have a drain in it. I would run the drain to the sea. I agree that you should look into Ozone your your tank it will be a great addition.

I already installed a drain on the collection cup. The next addition should be an ozone. One of my props is acting up and needs replacing, so probably after that

Wow not to bash you at all but you did not think about evaporation on a 18,000 gallon out door reef pool. This should have been planned out from the start on a build this scale. I also would not be using the sea water from right behind the tank and fish farm as you seem to be. All the boat traffic and being right on the shore like that there is a high amount of run off pollution. When large scale public aquariums use NSW the collect it out from the middle of the bay (using Monterey Bay Aquarium for reference) and then they still UV and Ozone treat it before it goes into the tanks. You may want to look into a large RO system for top off. As for salt water here in the States there are many companies that sell filtered clean natural sea water, you can by it by the tanker or seven as small as 5 gallons.

Thanks for the comments. I think you should be here to understand the complication of the system. Evaporation was a factor from the start but running a semi-open system did the trick and the water actually cleared up very well without the skimmer or any other type of filtration. Remember I only have local fish and corals and they are used to the type of water in the tank. The NSW being added to the water is being pulled from 20 meters in and around 6 meters under. However, the water quality in the bay in front of me isn't that good to start with and therefore I run into problems. We were actually planning to get 'good' NSW from somewhere else and start routinely adding it to the system. This, in cost, will be similar to bringing in fresh water. The tankers I use have around 1,000 gallons but I think I can get larger ones if need be.

shes skimming alright.. very impressive build. I bet you couldnt fall asleep some nights thinking about this. Haha.

It is a continuous thought of what could be changed/enhanced/removed/adapted :lmao:

the public aquariums also filter it through a sand filter. UC Santa Barbara pumps their water through a 20 micron sand filter, no ozone or charcoal. and theirs is a few hundred gallons a minutes flow through system through the school's marine science dept and back to the bay.

The idea of a sand filter was brought up early in the project. Local aquariums here use it as well before adding the water to their holding tanks. Funny enough though, I don't have neither a fresh water nor a saltwater holding tank because of the lack of space :lmao:

If I can get a big enough holding tank for the NSW, I want to install filtration systems on it and let it run through it for several days or a week before adding it to the main system. This way I can make sure the water I'm adding is acceptable. Right now though, I am doing the best with what I have

 

[Reefski's]

what the University does is pump continually into the system. that seems better than running the pump to "filter" the water more than one pass through the sand filter.

the way they do is to pull the water through the sand filter and pump that water above their system where it gravity feeds to the tanks and back to the sea.

 

[Kerreefer]

what the University does is pump continually into the system. that seems better than running the pump to "filter" the water more than one pass through the sand filter.

the way they do is to pull the water through the sand filter and pump that water above their system where it gravity feeds to the tanks and back to the sea.

:thumbsup:
Thats a good idea. i would think the best route to incorporate that is to run a 2 stage/speed supply pump from the ocean water there... float activated switch to send it to full speed when the water level is getting low from evap. then kicks back to low speed just for fresh sea water circ. heck, you could put a frequency drive on that and set it for variable ramping. it would be, in the end, more efficient.

also to think about it, if he is running constant slow recirc., he would not have to worry about FW top off. the seawater will reajust that continuously.
... that is, if it gets enough recirculation. too slow and would end up with Some salinity rise.

 

[walnuts24]

Been almost 3 weeks, any updates?

 

[nahham]

Been almost 3 weeks, any updates?

WOW.. time really does fly

• We installed the collection cup but it seems it still needs some more tweaking before it can be used.
• Planted nearly 40 mangroves in the mangrove section in the fish farm. It turned the water green for some reason, at least I think it is the mangroves, we didn't change anything else.
• I am playing with the idea of an algae scrubber. The mesh is starting to collect algae but the water flow isn't optimum so I'm changing the design a bit.
• Going tomorrow to see some sand filters that might work for my setup.

Photos soon...

 

[thelizardkin]

can you post a how to on that skimmer

 

[nahham]

Updates

Updates

As I mentioned before, the water suddenly turned green after adding the mangroves. Doing extensive water changes does not seem to help either. I'll let it settle for a bit before I take drastic measures.

A view of the skimmer top.

A close-up to the skimmer skimming. Small bubbles and never-ending skimate. I decreased the amount of air going through the venturi through the use of a valve.

My mangrove section.

My algae scrubber experiment.

 

[nahham]

can you post a how to on that skimmer

It is really not that complicated. You can find the semantics of the skimmer, neck, and collection cup here.

The water coming into the skimmer body goes through a pipe that goes midway into the body. The output comes from a pipe that goes all the way to the bottom of the skimmer body. A valve is placed on the output pipe to control the flow. Any particulars you want to know more about?

PS: I would of made the collection cup's height a bit taller since right now all of the skimate is coming out of these holes because of the airflow.

 

[kinlayan]

Nahham if i may give some input..... you arent going to get good scrubber results with that small screen , as it is way too small for your volume plus it doesnt get any more light than the rest of the tank and fish farm which is the key for a scrubber, at night it should be illuminated and needs to be much larger. I fear with that experiment you will think scrubbers dont work, the thing is they need to be properly sized with sufficient flow and lighting to make the algae thrive on the screen more than it would anywhere else.Have a look at Walter Adey's book "Dynamic Aquaria" for good info on large scrubbers!

Ozone and or UV will sort out your green water the fastest, but please use it in a suitable ozone resistant reactor.

Best of luck!

 

[nahham]

Nahham if i may give some input..... you arent going to get good scrubber results with that small screen , as it is way too small for your volume plus it doesnt get any more light than the rest of the tank and fish farm which is the key for a scrubber, at night it should be illuminated and needs to be much larger. I fear with that experiment you will think scrubbers dont work, the thing is they need to be properly sized with sufficient flow and lighting to make the algae thrive on the screen more than it would anywhere else.Have a look at Walter Adey's book "Dynamic Aquaria" for good info on large scrubbers!

Ozone and or UV will sort out your green water the fastest, but please use it in a suitable ozone resistant reactor.

Best of luck!

This was my pilot research. I have the capability of expanding it further through the other overflow holes I have. I just wanted to make sure algae will start growing on it, which it did. The current screen is 1.3 x 1 meter.

Thank you for the reference, I will look at it.

 

[mr.wilson]

Algae filters can do wonders, but I haven't seen any evidence that they work any more efficient out of the water or through the use of screens.

I dont want to discourage you, but mangroves are another inefficient method of nutrient export and assimilation of nutrients. They look nice and have their place in the ecosystem so I would use them, but if you are still managing water quality, then place them in planters above the tank on a drip watering system and fill that cement tank with caulerpa indigenous to the area. Macroalgae will take off in their.

I don't want to sound like a broken record, but one of your major issues is the spectrum of light at such shallow depths. A colour temperature corrective shade cloth will filter out much of the 510-630 nm light that is causing the phytoplankton to proliferate.

I assume your phosphate levels are high? Lanthanum chloride dosing is the most cost effective and rapid method of starving algae of nutrients in such a large system.

Coagulants, such as Kent Pro-Clear will clarify the water and help a sand filter and diatom filter collect the free-floating algae.

Perhaps increasing the flow at the surface will also help.

Collecting local Rotifers will help consume the phytoplankton naturally and add to the food web.

... And when all else fails, ozone and UV will easily handle the problem.

What do you feed the tank with? Perhaps this is a source of phosphate as well.