Bare-bottom tank - HDPE board questions

[skyrye7]

Hi

I have just siphoned out all my sand and am planning to go bare-bottom.

The rocks are also out so only the fishes are left in the tank for now.

I read the forums and most people suggested to put a starboard/HDPE on the bottom to cushion in case the rocks slide.

I have some questions about the starboard/HDPE:-

1. Will it float before I put the rocks and if I do not silicone it?

2. Anyone has experience of not using silicone...I am wondering if it will result in lots of detritus being stuck beneath the starboard/HDPE

 

[NastyZ]

I wouldn't do it unless your going to silicone it your going to get a lot of build up under it I'm Bb on my glass only I haven't had any problems

 

[skyrye7]

BB on the glass is an option but i want the black color on the bottom to counter the reflective nature of the glass

 

[cambo123]

I actually just switched back to sand....but I used a white starboard bottom without silicon for about 3 months. It will float without a rock which makes it kinda annoying to put in and aquascape. My only issues was I had the board cut to fit just inside the silicon seams for the tank. I thought that the detritus that would get stuck down there would be easy to siphon out. This proved to be incorrect because the diameter of the siphon hose was larger than the gap between the glass and the starboard. So, make sure you have it cut for at least a 1/2 inch gap all the way around.

 

[skyrye7]

Is there a lot of detritus build up?

Also since you mentioned that it will float without the rocks, once you put in the rock will the edges float?

 

[cambo123]

Yes, there was a lot of detritus build up. It is actually fairly incredible how much you get. As I mentioned above, the issue was that I had only about 1/8" gap between the tank glass and the starboard. I thought (incorrectly) that the siphon hose being 1/2" would still suck it up. This doesn't really work. You really need to be right on top of the detritus to suck it up. Just make sure the gap between your starboard and glass is at least as large as the diameter of your siphon hose. I did not notice any detritus under the board

My piece was firm enough that there was no flex. It did not float at all once the rocks were on. The board sat flush with the glass.

 

[skyrye7]

Hi

I am not sure if I understood correctly what you meant. Hence am drawing it out for your help to verify.

Not sure about your explanation between the gap of the HDPE & silicone.

Is it as per Image 1 or 2?

Thanks

 

[skyrye7]

bump

 

[MikeC120]

Yes.
Make sure you have a 1" gap all the way around the bottom of the tank.
I was told silicon does not adhere to HDPE so I did not use it.
I have two tanks set up with HDPE (one for a year and a half) and have had no problem with detritus under the Board.
My concern with using silicon is if you decide to use it and don't get it perfect you could actually be creating a detritus trap if it's not sealed completely.
The only suggestion I can make is spend the extra money and use 3/4" board this is heavier and may help keeping it down. I put my rock right on it so I'm not sure about the 3/4" floating?

Hope this helps

This is a pic of the 30 gal when it was first set up so you can see the gap.

 

[GroktheCube]

I only finished removing my sand fairly recently, and a good portion of the bottom is already encrusted with coralline. I'm not sure how much of a difference the starboard would make in terms of appearance in the long term unless you intend to scrape coralline off of it.

 

[MikeC120]

Appearance is going to be the same IMOP.
The main idea for me with the HDPE is
1. Glass protection
2. Ease of maintenance, if you have flow pointed at the bottom of the tank, all the detritus that don't flow up and into the water collum should go into the 1" gap for ease of siphoning.

 

[skyrye7]

Hi Mike

So your explanation would be as per my image 1 or 2?

 

[Scorpius]

Why not glue some pvc pipe that is about half and inch long on all four corners to raise the starboard off the glass. Kind of like feet on a couch. Then the detritus wouldn't get stuck.

 

[MikeC120]

Hi Mike

So your explanation would be as per my image 1 or 2?

I went with one inch gap all the way around the tank plenty of room for a siphon hose.
Measure he inside of your tank from glass to glass then minus two inches(1" on each side) on each dimension and that's your size.

If your tank is 48x24 you would order the HDPE 46x22
I cut out my overflow box with a jig saw.

 

[cambo123]

skyrye7, yes image 1 if I am understanding it correctly is correct!

I recommend at least 1/2" gap. So if your tank has internal dimensions of 20x20 shoot for an HDPE dimensions of 19 X 19.

 

[skyrye7]

Hi

The inside of my aquarium is not flat. As you can see in the picture below, There is a 1 inch internal glass bracing all round the aquarium.

So should the HDPE leave a 1 inch gap between the bracing and the HDPE? Or should it fit nicely and leave no gap?

 

[MikeC120]

If it was me I would leave a 1" gap so you can see the glass in-between the brace and the HDPE