Zoological Aquascaping

[greech]

Yes, you can run 1.020 if you are keeping the appropriate animals. Keep in mind that the higher/lower your SG, the higher/lower the concentrations of elements will be as well as salinity. A tank run at 1.020 will have less calcium, etc. than a tank kept at 1.025. Granted those elements can still be diminished significantly and the SG will remain the same but as a general rule, the higher the SG, the higher the element content will be. That is even more important on a small nano that is not being dosed (perhaps you will?) and is reliant on water changes for nutrient removal as well as element replenishment.

DO NOT use 2 pumps to move water back and forth to the display and sump. That will not end well. You need a siphon/gravity drain to bring water to the lower tank (yes, your sump/refugium can be above your display but see below). If you use a 10 gallon, it will not be predrilled and drilling a 10 gallon is tricky due to the thin glass (take it to a glass shop if you do this). Drilling would allow the installtion of a number of different overflow boxes (important for surface skimming and noise control). Some of those boxes are very low profile. Other options is a small HOB overlow box that either runs on a siphon (then gravity) to take water to the lower tank. Lots of options out there for drains including simple PVC DIY drains (not a propoenent of these myself). I understand you wanting to keep the display clean but there just is not another way to safely move water.

Lack of a baffle in the lowest tank leads to the entire water level in that tank being variable as evaporation occurrs. A baffle will maintain the height in one section and evaporation will occur in the other (where the return pump is located). Water always evaporates at the lowest point first. I am not sure if you are planning on using a submerged skimmer in your sump but if you do, you will want to have at least one baffle to maintain the water height that the skimmer sits in.

 

[MudskipperFan]

Yeah, I figured that using a lower salinity would limit me to tidepool animals or animals that are capable of living in estuarine habitats, because from what I've heard animals that live in deeper water live in the water where there's more/stable salt content. Then again, I've seen anemones, mussels, barnacles, and crabs at my local estuary so it's seemingly not too much of a loss of what to add to the tank.

As for the pumps, I only have one and was originally planning to just use that one, but wouldn't have a clue on how to move the water back from the sump to the tank. Your explanation helped but if it were possible to show a diagram or something it'd also help, because Google searches haven't thrown me back anything. I initially wanted to use a sump for aesthetic purposes and sanitary purposes and to omit as much filtering devices as possible from the main display but I might actually stick with an HOB or something as simple as possible if it can suffice for the tank. Either way, your advice is most definitely appreciated and I might actually be able to make this idea turn into a reality, so thank you.

 

[greech]

Very simple diagram here...

http://www.melevsreef.com/allmysumps.html

 

[authmal]

The pump would rely on some kind of tubing (PVC or vinyl, with PVC being preferred) from the pump (in the sump) to the return in the tank, probably some type of spray bar in your case. The only concern is whether your pump has enough strength to move enough water at the head height (how far it has to move water up) to be sufficient. Getting water into the sump can be as easy as using a HOB overflow and letting gravity do the work.

I'll be the first to admit that my knowledge here is a bit (okay, a lot) sketchy, but as things currently stand, we're looking at a 75 gallon saltwater set up with a 55 used as a sump next year, so I've been acquiring information. At some point, I'll be putting together a solid list of parts. I'm pretty sure my stock list isn't going to change, because there are only so many fish I'm interested in keeping *and* am willing to meet the care requirements for.

 

[MudskipperFan]

Thank you for the diagram and the advice. I've found some info on chamberless sumps. It's kinda interesting even though it's probably gonna involve me drilling into the tank lol. If I wanted to make a makeshift sort of chambered sump, would I be able to use a smaller (1-5 gallon) tank inside the main sump to act as some sort of baffle or overflow for the water?

 

[greech]

I'm sure there is a way but the water in the rest of the sump would need to stay below the smaller tank.

 

[MudskipperFan]

Yeah, figures. Is it also possible for me to make a homemade canister filter and conceal it from the rest of the display? That's recently been a part of my considerations.

 

[authmal]

Yes, but it's been mentioned that a DIY canister filter, while perfectly functional, is going to cost as much as, or more than, a perfectly functional budget model. For a tank your size, I would definitely *not* go any larger than something like a Sun Sun 302/Aquatop CF300, and even with those, you'd probably want to point the spray bar upward at at an angle toward the side of the tank to disperse flow.

I'm not sure how well a canister filter would work for marine setups, however. The canister itself would be fine, but I recall reading that a lot of filters end up causing problems with nitrate levels unless there's frequent maintenance done, and that's part of why sumps are more commonly in use than canisters/HOBs on marine tanks.

 

[MudskipperFan]

Hmmm, do you think it'd be possible to add macroalgae to the canister like I would in a sump, to control the nitrates?

 

[authmal]

Probably inefficient and ineffective to do so.

No light source.
Macroalgae should be fast growing, so it should be easily accessible so the growth can be managed.

You'll be better off with some kind of HOB refugium or in sump refugium, just due to the ease of accessibility.