Any reef / aquarium experts in TEST?

[DirectorGunner]

So I'm going all out for my Son's new hermit crabs (TBH it's also for me lol) and working on converting this tank and cabinet stand
into a perfect eco system for them.
http://www.exo-terra.com/en/products/natural_terrarium_large.php

So that a mini ocean environment is on the left and a freshwater lake environment is on the right.

Spoiler: Background info

Hermit crabs need both freshwater and saltwater. They rarely breed in captivity as they lay their eggs in the ocean. Changing their water every day is a pain in the ass. So.... little ocean on the left for their saltwater needs and breeding... and little river lake on the right for their freshwater needs. Ecosystem solved! They also need an exact temp gradient available in the tank which I've figured out and have automated. And, if you can imagine, 90% humidity, I will have that automated as well. And this is all still in tandem with my hydroponic systems I am still working on. While doing loads of school work.. and handling clients.. lol fml need more hours in a day.

Please ignore the messy silicone application (I'll deal with that eventually).
I have to create ramps (doing so out of rocks) so that the hermit crabs don't get stuck in either waterside.

Also covering the back with rock and ledges and will attempt to grow some vine vegetation up the back wall.
Right freshwater side will have some live plants too that grow really easy and don't get big.


In order to increase water mass for both left salt watersides,
here's where I need help,
I am putting two 16 inches deep by 8 inches wide by 12 inches tall (couldn't find 14-16 inch tall in this configuration for a good price) sump filter tanks
in the bottom cabinet which leaves room in between them for electronics and the fogger.
These tanks will allow the water mass I need to keep these little water sides cool and healthy.

This is what I have in Fusion360 atm. It's 2 inches taller from what I ordered, getting an extra two inches would have cost over $200 more so.. yea.. 12 is fine.

I need help figuring out where and how many baffles to add to the tanks.
And what chambers I should add in addition to that.
Sketches over my image would be most helpful!

I'll be drilling a 1" 1/4 hole through the bottom of the tank x4 times through the cabinet to the sump filter tanks.
Adding PP 1/2 bulkheads, the returns will be elevated as it not allow water to drain completely if pumps fail.
Closed-loop both sides, the back will have a small waterfall on each side and return to sump near the front on each side for their respective sump tanks.
I hope that makes sense? English hard... lol.

 

[PattyTheCake]

Please excuse my crude attempt at MS paint but this is pretty much what i had for my sump on my salt water tank.

 

[Talonsbane]

I'm an expert on knowing nothing about yet still appreciating the aesthetic of this subject matter. So while I'm no effective help, I'll still lend my support that you'll do great.

 

[DirectorGunner]

Please excuse my crude attempt at MS paint but this is pretty much what i had for my sump on my salt water tank.

Thank you!
Do you think I'll need an overflow chamber in my setup or you think this setup is sufficient?
I may even be able to skip the protein skimmer since I won't have fish or anything in the salt waterside?

ah! I can replace the protein skimmer with a UV light!

Edit:
Your paint skills are better than mine! lol
Here's what I'm thinking maybe, based on your example

 

[PattyTheCake]

Thank you!
Do you think I'll need an overflow chamber in my setup or you think this setup is sufficient?
I may even be able to skip the protein skimmer since I won't have fish or anything in the salt waterside?

ah! I can replace the protein skimmer with a UV light!

Edit:
Your paint skills are better than mine! lol
Here's what I'm thinking maybe, based on your example
View attachment 16499

Looks good to me! I had live coral and fish and all sorts of other creatures, so I needed a skimmer, and my UV lights where above the aquarium. A skimmer would just help keep the water cleaner from all the crab poop and their messy eating, but isn't so essential if you don't have live coral.

I'm not 100% sure what you mean by overflow chamber. Do you mean an overflow box in your tank? I had them in my aquarium, but that had water filled right to the top. If I'm understanding your plan with your aquarium it's just to have a bit of salt and fresh water on either side, but not to fill the tank, correct? I think just some type of screen or a very short overflow box on your return in your aquarium that will stop any creatures from getting sucked into the sump would be sufficient. Also the height of your return in your aquarium will dictate how high your water level is.

But if you're talking about having a place for excess water to go in your sump, which I think is what you're getting at, then so long as the baffles in your sump don't go all the way to the top, then any excess water will just fill up the other chambers of the sump which isn't a big deal, it'll sort itself out when the pumps start running again. If you do have a baffle all the way to the top, then if that chamber overfills it will spill onto the floor instead of another chamber in the pump. And don't have so much water in your aquarium and your sump combined that would exceed the full capacity of the sump, because if your pump quits all that extra water is going to end up running over the sides of the sump and onto your floor.

 

[PattyTheCake]

Choosing an Aquarium Overflow - Bulk Reef Supply

Bulk Reef Supply - Saltwater Aquarium Supplies for Reef Tanks

www.bulkreefsupply.com

found this, it's a pretty good read on how the overflow boxes work and why they're a good idea. but of course that depends on the size of your aquarium and your desired water level. and you could always make your own custom one.

 

[BUTUZ]

Total reefer expert here ask me anything you wanna know.

Had my fair share of crabs too.

 

[Sraika]

when i was really little we had a bunch of hermit crabs
i remember we'd draw things on the shells and change their names based on which shells they happened to be in
...im afraid im no help with the technical stuff tho, it's been a while lol

 

[DirectorGunner]

Total reefer expert here ask me anything you wanna know.

Had my fair share of crabs too.

Did you ever manage to get your hermit crabs to breed? ... oh wait... was that all a Dad joke? lol

@PattyTheCake Thank you so much for all the advice, I will look for glass panels to order to cut to size.

 

[DirectorGunner]

K, BOM is done.

 

[BUTUZ]

Did you ever manage to get your hermit crabs to breed? ... oh wait... was that all a Dad joke? lol

@PattyTheCake Thank you so much for all the advice, I will look for glass panels to order to cut to size.

Sorry, got the dad bod so need dad jokes to go with my belly.

 

[PattyTheCake]

ooooh fancy!

 

[DirectorGunner]

Any recommendations for the right pump to get for both sides?
I assume it's about a half-gallon of water inside the hermit crab tank on both sides.
Something to allow 5-10x replacing the hermit tank water per minute.
As that's the recommended flow rate for saltwater tanks afaik.

 

[PattyTheCake]

Well, if it's half a gallon of water and you want it to replace the water 5-10x per minute, then you'll need a pump that can do 2.5-5 gallons per minute, or 150-300GPH or 600-1100 liters per hour (I'm Canadian). That seems pretty fast to me for such a small volume of water, so I just did a quick look and some sources say the water should change over 4-5 times every hour, so 0.5 gallon times 5 changes per hour gets us a pump that does 2.5GPH. The smallest pump I've been able to find with a quick look is 50GPH. So I guess I would recommend whatever the smallest pump you can find that doesn't have a high pressure flow haha. I would also recommend a submersible pump.

I checked amazon just now and there's some small ones that have adjustable flow rates that might suit your needs.
Something like this https://www.amazon.ca/dp/B008OCZUK6/ref=cm_sw_em_r_mt_dp_U_0PY4EbJMJV99B

 

[Talonsbane]

Back in 2008, I worked for a fabrication company that designed & created unique tools items for tech processing which often dealt with various chemicals. From what I remember, you will probably want to make sure that the pumps you use for each side of the tank is designed to allow for that sort of fluid as some deal with salinity more easily than others, but might be more expensive as well.

 

[DirectorGunner]

When you put it like that, yea I think 5-10x per minute is way too fast, I think once per minute or slightly less wouldn't be too fast. So like 40 to 60GPH because I also have to account for pressure loss due to lifting and plumbing.
Been looking here for inspiration.. not finding a good quality one for a nano tank yet, DC variable marine pump.
https://www.bulkreefsupply.com/pumps-plumbing/submersible-aquarium-pumps.html?order=price&dir=asc&limitAjax=80

 

[PattyTheCake]

If you were in Canada I could tell you what a good place to shop at would be, but I know they don't ship out of country. Atleast with an idea of what it is you need you'll be able to find something eventually, I'm sure. And @Talonsbane has a good point about making sure a pump is good for salt/fresh water, I didn't think of that.

 

[DirectorGunner]

Seems the best one I could find for low GPH is this one
https://www.amazon.com/gp/product/B078WHWG2Y/

Which can be adjusted down to 220GPH. If I add some stainless steel mesh staggered on the inflow into the tank, I should be able to reduce it further by creating more resistance.
The problem is if I go for cheaper than $60 for a DC marine return pump.. it starts getting more unreliable and no controller, from what I can see from results and reviews.

It doesn't have a built-in float or pressure difference sensor so might get this for an emergency off if the return pipe into the sump gets clogged and the pump starts filling up the hermit crab aquarium using sump water.. can at least stop that from happening with a water level sensor relay on the outlet powering the pump.
https://www.amazon.com/gp/product/B07BRXX9VW/

 

[PattyTheCake]

I'm curious to see how that all works out! Sufficiently long piping may take up some of the extra pressure if that's a problem, too. So long as your water isn't too turbulent for the crabs or starts swirling around your substrate I would imagine you'll be fine. And the water level sensor is a great idea too! I didn't have anything like that and my water level in my sump got dangerously high a couple times...
I've never dealt with such a small volume of water, my tank was 144 gallons and my pump was something like 800GPH. Totally different applications and setups.
I'm really excited to see how all your final setup turns out! Makes me want an aquarium again haha

 

[Talonsbane]

So, I'm waking up after some bizarre thoughts & the thing on my mind is how to diffuse the suction if the water pressure to soften it for the crabs & their young. The idea of using an aquarium bubbler hooked up in reverse with a fine mesh / sponge filter over the holes seems like it might help with this potential problem. Let the water enter the area via waterfall / cascade & then be drawn out from below the false floor that would be over the sponge. You might have to seal some of the holes closer to the water inlet though to ensure that the water cycles through the area best.

LoL I feel like the character Laslo from the old Val Kilmer movie Real Genius.