Hiatt filtration system

[ColaAddict]

thanks for the advise Cory. One more thing, can I also do a deep sand bed with the hiatt system, or is DSB not necessary or will not be effective, because the aerobic bacteria will outcompete the anaerobes for food?

[CoryDude]

thanks for the advise Cory. One more thing, can I also do a deep sand bed with the hiatt system, or is DSB not necessary or will not be effective, because the aerobic bacteria will outcompete the anaerobes for food?

I don't see why you couldn't go with one, but it would be more for looks than functionality. For a while, I was using a sulphur denitrator, which uses the same anerobic bacteria as a dsb, and the hiatt. But, I could take either one off line and never see a difference in the tank.

[CaptainGreg]

I'm doing research on Hiatt system and I was reading through this thread. Why do you think that the pH rock is junk? Also, I want to set up a Nano with Hiatt. Do you guys think it's really necessary to have the outflow above water? Has anyone have success running outflow underwater?

The water flowing out of the filter does not have low enough PH to desolve it. It is a type of marble and it take PH less than seven to desolve it. The gravel was too expensive and it require more pump power to have it go through gravel container.

I use the Sea lab block to supplement cal and other trace element.

I do not have the out put above the water. I have it under the water, but make sure you have enough surface water egitation for air exchange.

[StevenSeas]

I believe another reason for the output to be above water and agitating the surface as much as possible is due to yes the low DO levels and the high dissolved CO2 levels.

However, it goes beyond this and if you have a high dissolved CO2 content then your pH will be lower. The higher the beginning pH is (>8.3) the more that it drives
this reaction causing the pH to go lower.

Also as far as the low DO and high dissolved CO2 content goes it important to help mitigate this anyways possible. This is because CO2 is 32x more soluble than O2 in water, and 02 is 2x more soluble than N2!!! This means that you have are going to have a more difficult time getting the CO2 out and O2 in. On top of that water can only hold so much stuff and since we are already at 35ppt salinty and about 78-80*F that means a total of 6.25ppm O2 can be in saturated tank water. And at and below 5.0 ppm there has been seen to be a decrease in feeding response and activity level of fish.

Not to scare you off at all but that is why I believe that it is recommended that you have the output above water level to help get as much surface area of the effluent water exposed to normal air to get as much O2 in and CO2 out. If done properly as many people have done before t shouldn't be an issue.

[StevenSeas]

Dont mind me I have just been getting no sleep for the past few days studying for this stupid Biology of Fishes exam and am just finally happy that I can put it all together and in a real world situation to boot.

[ColaAddict]

but if I just let the RN bacteria populate the live rock and sand in the main tank of my Nano, won't the water be aerated when it flows through my overflow? I think that what the Hiatt people use are torpedos where the bacterial reaction happens in the torpedo and the water needs to be oxygenated after it comes out of the torpedo. isn't that what happens when water leaves my display and flows out of the overflow?

[StevenSeas]

Yes it should get adequately aerated when going through an overflow or the diff levels off a sump or out the return. The main problem I thought of/was adressing was if the torpedo had a designated sole purpose pump and return line both of which were under the surface. If this was the case then at night you could run into problems with low DO. This is because the photosynthetic algae that produces O2 during the day actually respirates and uses up O2 at night thus possibly putting your tank into a low DO situation if the returns weren't adequatley oxygenated.

[CoryDude]

I had the torpedo on a dedicated loop in the sump and tried various layouts to minimize noise and splashing. I ran the filter with the return underwater and never had a problem with low oxygen levels. However, my system wasn't a nano either.

From speaking with Bill (aka Snake) the main factor for keeping the returns above the water and providing a high flow rate is to keep the DO levels as high as possible (almost to the point of supersaturation) and increase the rate at which the RN Bacteria function.

[ColaAddict]

So, do you guys recomend the Hiatt, say, if I'm just planning on growing softies and fish in my nano? Or does it pose more problems in the long run due to depletion of nutrients?

[Bill S]

If I had a FO or Fish + softies, I'd go with a Hiatt again. I still have one torpedo, just in case I go back that way.