lowering weir height

[LDG]

Im setting up a new tank(180x80x80cm), and the water runs really high ,because the height of the weirs are only 20mm bellow tank height,i was wondering if there was a way to lower the height of the weirs without taking them out and cutting the glass. the thickness of the weirs are 12mm glass. I tried decreasing the flow rate of the pump but no change in water level.Is there a way to grind 10mm of the height, or should i just live with the water level being really high?? thanks leon...

[BlakeyBoyR]

Whats to stop you from drilling holes in the weir at a lower height and covering them on the inside of the weir with a non UV treated fly screen? that way the water should be drawing in from lower, as well as higher, and thus the water may not stay up as high. Particularly if you make the holes large enough as to draw so much water in that the actual over flow effect becomes redundant.

[LDG]

yeh i asked the tank builders that and they said they could not drill near the top of the weir without risk of cracking , and if to low the sump will not be big enough to hold all the water as it drains and i have a 4ft sump????

[Matthew]

G'day

I know it sort of defeats the purpose of the weir but you could build an overflow box, maybe even inside the existing weir. This would lower the height of the water and also leave the possibility of a saftey option should the overflow box fail then the original weir would begin to operate.

I like the idea of removing the weir and cutting it down to a better height OR (better still cutting the glass in the tank, if they think it may be possible), but this of course involves a fair bit of extra expense, but then again you won't have to worry about overflow boxes.

If you really want to grind the glass down then you could use a glass grinder, but I don't know if it would work on that thickness of glass. Glass grinders are used in lead lighting. and normally operate on unfixed glass that is brought to the machine.

Anyone else have any ideas?

Matthew

[ViS]

I'd say you'll save a lot of future heartache if you remove the wier and cut it down, then silicone it back in (get it done by a professional).

You mentioned it was a new tank? Was it a manufacture mistake?

A 31" high, 1100+ litre tank is not something I'd be fiddling with for the sake of saving $50 by not getting it done right.

[CThompson]

I know it sort of defeats the purpose of the weir but you could build an overflow box, maybe even inside the existing weir. This would lower the height of the water and also leave the possibility of a saftey option should the overflow box fail then the original weir would begin to operate

This won’t work Matthew as the hight of the existing weir is still there.

However, I would ask the question, why is the water level “too high”?

If it does not touch the underside of the bridges or the lids, what’s the problem?

If you are concerned about “something” happening that suddenly increases your tank’s water level, and causing an overflow, that won’t happen.

If the water level is not touching the underside of the bridges or lids, I say well done tank maker for their accuracy.

If you still want to alter it, your best option is to cut the weir out, resize it, and glue back in again.

Craig

[wui39]

One posible reason that I can think of and this will affect me as well when I get my new tank, "certain" fish do better when the water level is not all the way up to the lids.

[Wayne]

hi all

if the tank is empty which i think is then the weir

can b cut and then tapped out

as long as u have enough room in the weir to tap it out

there shouldnt b a problem ur weir should b atleast 150x150 if so have a go

i think what worst senario new weir not tank

or call me some time in the new yr

cheers wayne

[LDG]

thanks every one for your input, i think i will get the tank builders to replace the weire at a lower height , they said they would come do it for free so i may as well.. leon

[CThompson]

You didn't answer. Why is the weir too high? When full does the water tough lids or bridges?

[hardb0iled]

My weir sounds about the same height as yours, I think its perfect, the water level will just touch the side braces if I crank my sump return pump right up so there is a bit of water 'backup' at the overflow. Unless you plan on keeping Archer fish?

[LDG]

the water level just touches the glass that holds the lids, about 5mm under the cross bracing.

[CThompson]

In that case, obsoletely yes the water level is too high. Follow through with what you have organised and get the tank makers to cut out the weir and redo it.

Weir hight can be dependant on the pump, if a pump turns your tank over 4-6 times per hour causes the water to hit the underside of the lids, bridges or glass that hold the lids, the tank maker has made the weir too high. 4-6 turn over times is not an unreasonable amount of water to be expected to turn over per hour, and it should have been made to accommodate this.

Craig

[LDG]

thanks Craig , my return pump is 6500lph, having the water level that high cant do any damage to the tank though can it??

[CThompson]

No it can't, but at the same time you can't have the water touching either. It must be fixed in my opinion. If the tank maker is going to do it for you at no charge, then let them. These fish tanks of ours are all made by hand, mistakes happen, the true character of a tank maker is if they will come to the party and remedy the situation. If your tank maker is prepared to fix it up, stick with them.

If you have issues, contact Wayne (above post) he will do the right thing by you.

Craig

[LDG]

ok thanks Craig..