Herbie Overflows and Fluval Bulkheads??

[malawi500]

My Fluval 1200 came pre-drilled from factory with two bulk heads with an internal diameter of 25mm each:



However, you then need to insert a special tube/fitting through the above holes which has two rubber o-rings to make the pipe water tight and gives a pipe underneath to attach any hoses.

This 'special pipe' however restricts the internal diameter to just 20mm. The inlet and outlet pipes are pictured below:



The filter strainer is removable and so are the outlets. The standard pipe is what needs to slot in the 25mm bulkhead thus reducing to 20mm internal diameter. The bit on the far left of each pipe is what is exposed under the tank for the hose to attach to.

Is it worthwhile removing these Fluval bulkheads and replacing with new? If so what? If I do this then surely it would make it so much easier to plumb in 2 new vertical pipes?

Or will 20mm pipe at full siphon be enough to flow 900gph which is what I am to achieve?

 

[malawi500]

I think I found my answer here:
http://www.beananimal.com/articles/hydraulics-for-the-aquarist.aspx

With a 20mm diameter and 36" head height will give me ~1300gph

Time to get me some pipe and crack on with this project ;-)

 

[malawi500]

Will this ball valve be suitable to throttle the flow:



?

 

[malawi500]

I've got myself some 32mm pipe. Anyone know how low below the 'normal waterlevel the main drain pipe should be?

 

[thecoolguy]

1) you will want a gate valve, not a ball valve - while it is possible to adjust a ball valve using a mallet or hammer (which i started with) - changing to a gate valve made life 10000000000% easier

2) i would say at least 5-7" or so? low enough where it won't cause a vortex and suck in air

 

[malawi500]

I missed this post, but I have gone for 3" below desired water level, and I have used the standard Fluval 405 as a strainer that sits on top.

I will now wait 24hrs for the silicone to dry before I test these new outlet pipes.

Now I need to find something suitable and large enough to act as my sump!! It needs to hold 20g, 10g of which will house my filter media and 10g as my reserve in case of power outage.

I need a valve that will fit inline with 25mm hosing, I'm not sure you can get gate valves for flexible hosing can you??

Also how do I go about filling the tank/sump and marking levels etc. in case of outage, max water level etc etc?

 

[malawi500]

If my tank is 90g, based on jcardona1's 190g discus tank whic had a 40g sump I'm guessing I'd need an 18g sump?

If I used half to hold the media and the other half in case of power outage that'd mean I could have up to 9g of filter media. Is that overkill for a 90g tank?

Bearing in mind my existing Eheim 2028 has 1.9g media? Even if I had a 10g overall sump that would give me twice as much filter media.

Am I overthinking this? What size sump would be ideal bearing in mind I will have it setup like this:



I will just use a 25 micron filter sock and the rest will be bio media such as Biomax and Substrat

 

[Spiritofthesoul]

a sump size of 1/4 the main tank size is the general rule of thumb. So a 90g would be recommended to have a sump of at least 15g.
Of course if you can go 18g that would be better.

 

[malawi500]

you mean 22.5g minimum as that's a quarter...

 

[malawi500]

Well I found a 21g plastic sump of food grade quality for just £5.99 in my local discount shop.

Will hopefully have most of it plumbed in by the weekend